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20_TIRDrainageReport
March 2019 TECHNICAL INFORMATION REPORT Talbot Hill CLR Installation Renton, Washington PROJECT NUMBER: 15060 PROJECT CONTACT: Stuart Toraason EMAIL: stuart.toraason@powereng.com PHONE: (513)326-1504 POWER ENGINEERS, INC. This page intentionally left blank. POWER ENGINEERS, INC. PREPARED FOR: PUDGET SOUND ENERGY RENTON, WASHINGTON PREPARED BY: POWER ENGINEERS, INC. 3 CENTERPOINTE, DRIVE, SUITE 500 LAKE OSWEGO, OR 97035 POWER ENGINEERS, INC. This page intentionally left blank. POWER ENGINEERS, INC. PAGE i TABLE OF CONTENTS 1.0 PROJECT OVERVIEW ................................................................................................................ 1 2.0 CONDITIONS AND REQUIREMENTS SUMMARY ............................................................... 5 2.1 CORE REQUIREMENT #1: DISCHARGE AT THE NATURAL LOCATION ............................................ 5 2.2 CORE REQUIREMENT #2: OFFSITE ANALYSIS ............................................................................... 5 2.3 CORE REQUIREMENT #3: FLOW CONTROL .................................................................................... 5 2.4 CORE REQUIREMENT #4: CONVEYANCE SYSTEM ......................................................................... 5 2.5 CORE REQUIREMENT #5: EROSION AND SEDIMENT CONTROL ..................................................... 5 2.6 CORE REQUIREMENT #6: MAINTENANCE AND OPERATIONS ........................................................ 5 2.7 CORE REQUIREMENT #7: FINANCIAL GUARANTEES LIABILITY ................................................... 5 2.8 CORE REQUIREMENT #8: WATER QUALITY .................................................................................. 5 2.9 CORE REQUIREMENT #9: ON-SITE BMPS ..................................................................................... 5 3.0 OFFSITE ANALYSIS .................................................................................................................... 6 3.1 LEVEL 1 ANALYSIS ....................................................................................................................... 6 3.1.1 Tasks 1-5 ............................................................................................................................... 6 3.2 LEVEL 2 ANALYSIS ....................................................................................................................... 7 4.0 FLOW CONTROL, LOW IMPACT DEVELOPMENT (LID) AND WATER QUALITY FACILITY ANALYSIS AND DESIGN .................................................................................................... 9 4.1 CALCULATION ASSUMPTIONS AND PARAMETERS ........................................................................ 9 4.2 PRE-DEVELOPED SITE HYDROLOGY (PART A) ........................................................................... 10 4.3 DEVELOPED SITE HYDROLOGY (PART B) ................................................................................... 11 4.4 PERFORMANCE STANDARDS (PART C)........................................................................................ 12 4.4.1 Area-Specific Flow Control Facility Standard .................................................................... 12 4.4.2 Low Impact Development Performance Standard .............................................................. 12 4.5 FLOW CONTROL SYSTEM (PART D) ............................................................................................ 13 4.6 WATER QUALITY SYSTEM (PART E) ........................................................................................... 13 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN ........................................................... 14 6.0 SPECIAL REPORTS AND STUDIES ........................................................................................ 14 7.0 OTHER PERMITS ....................................................................................................................... 14 8.0 CSWPP PLAN ANALYSIS AND DESIGN ................................................................................ 14 9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT 14 10.0 OPERATIONS AND MAINTENANCE MANUAL .................................................................. 14 11.0 REFERENCES .............................................................................................................................. 14 TABLES: TABLE 1 LAND COVER SURFACES ...................................................................................... 10 TABLE 2 HISTORIC HYDROLOGICAL CHARACTERISTICS ............................................. 11 TABLE 3 DEVELOPED HYDROLOGICAL CHARACTERISTICS ........................................ 11 POWER ENGINEERS, INC. PAGE ii FIGURES: FIGURE 1 TIR WORKSHEET ....................................................................................................... 1 FIGURE 2 SITE LOCATION ......................................................................................................... 2 FIGURE 3 DRAINAGE BASINS, SUBBASINS, AND SITE CHARACTERISTICS .................. 3 FIGURE 4 SOILS ............................................................................................................................ 4 FIGURE 5 DRAINAGE REVIEW FLOW CHART ....................................................................... 8 FIGURE 6 DEVELOPED HYDROLOGY AND MITIGATION PLAN ......................................... FIGURE 7 EXISTING POND SCHEMATIC ................................................................................... APPENDICES: APPENDIX A TIR WORKSHEET APPENDIX B WWHM (2012) MODEL RESULTS APPENDIX C LEVEL 1 ANALYSIS APPENDIX D OPERATION AND MAINTENANCE APPENDIX E FACILITY DESCRIPTION AND BOND WORKSHEETS APPENDIX F GEOTECHNICAL REPORT APPENDIX G CSWPPP APPENDIX H PREVIOUS TIR BY HDR POWER ENGINEERS, INC. PAGE iii ACRONYMS AND ABBREVIATIONS CFS Cubic Feet per Second CLR Current Limiting Reactor CSWPPP Construction Stormwater Pollution Prevention Plan LID Low Impact Development PGIS Pollution Generating Impervious Surface PGPS Pollution Generating Pervious Surface POC Point of Compliance TIR Technical Information Report WWHM Western Washington Hydrology Model POWER ENGINEERS, INC. PAGE 1 1.0 PROJECT OVERVIEW The Talbot Hill Substation is located at 2400 South Puget Drive, Renton, WA 98055. Puget Sound Energy (“PSE”) and Bonneville Power Administration (“BPA”) have two adjacent substations on Talbot Hill in Renton. Transmission level bulk power is received by PSE via the Talbot Hill substation from BPA’s adjoining Maple Valley substation through two 230 kV transmission line interties. Puget Sound Energy has modernized the Talbot Hill substation over the last two years. During construction of the first phase of the modernization effort, additional analyses completed by BPA revealed that the new equipment configuration at the Talbot Hill substation could cause significant impacts to BPA’s substation equipment during an electrical fault event because of the interconnection. To mitigate that potential, BPA and PSE have been working together to determine a solution to the problem. The best solution is to install current limiting reactors (“CLRs”) on the transmission lines that connect the two substations. The CLRs act as a large surge protector to protect the substation equipment should an electrical fault occur. The project consists of installing six CLRs, one for each phase of the two transmission line interties. The CLRs are large, highly customized coils that are each supported by insulators. For safety and security purposes, the CLRs will also be installed on elevated pedestals with foundations and enclosed by an eight-foot security fence. A new 190’ long by 85’ wide gravel pad will be constructed to support the CLRs and the enclosure. The equipment will be accessed by a new approximately 330’ long by 15’ wide gravel access road that will originate on PSE parcel number 2023059003 from the Talbot Hill substation driveway. The site improvements for this project include 0.42 acres of new impervious surface including a gravel pad for the CLRs and an access road. The total acreage for this project is 0.56 acres of development. The proposed expansion will be graded to the south to drain to the existing pond located to the south of the expansion area. The control structure in the existing pond will be modified to control the additional impervious flow from the proposed pad. The new access road will be constructed at existing grade and to maintain existing drainage patterns to the extent possible. Site vegetation is a mixture of barren land, grass and shrubs. The site appears to have been previously cleared. Slopes are moderate to steep and range between 1% and 16%. The existing substation and detention pond were designed by HDR Engineering, Inc. (HDR). The Technical Information Report (TIR) by HDR, is included as an Appendix in this report for reference. FIGURE 1 TIR WORKSHEET Refer to Appendix A. POWER ENGINEERS, INC. PAGE 2 FIGURE 2 SITE LOCATION POWER ENGINEERS, INC. PAGE 3 FIGURE 3 DRAINAGE BASINS, SUBBASINS, AND SITE CHARACTERISTICS POWER ENGINEERS, INC. PAGE 4 FIGURE 4 SOILS A soils map is below. Refer to the Geotechnical Engineering Services Revised Report for the Talbot Substation Improvements dated February 1, 2017 and subsequent Addendum Letter for the Talbot Hill Substation CLR Improvements, by GeoEngineers, dated January 29, 2019. The report and addendum letter are in Appendix F. POWER ENGINEERS, INC. PAGE 5 2.0 CONDITIONS AND REQUIREMENTS SUMMARY The project is subject to the City of Renton Municipal Code and the requirements of the City of Renton Surface Water Design Manual. The project will result in greater than 2,000 square feet but less than 50 acres of new impervious surface and so is subject to a Full Drainage Review warranting analysis of all nine Core Requirements. 2.1 Core Requirement #1: Discharge at the Natural Location The flows from the project will sheet flow into the existing pond to the south of the proposed expansion. The existing pond provides flow control for the developed site runoff. 2.2 Core Requirement #2: Offsite Analysis Refer to Section 3.0 of this report. 2.3 Core Requirement #3: Flow Control Refer to Section 4.0 of this report. 2.4 Core Requirement #4: Conveyance System Refer to Section 5.0 of this report. 2.5 Core Requirement #5: Erosion and Sediment Control Refer to Section 8.0 of this report. 2.6 Core Requirement #6: Maintenance and Operations Refer to Section 10.0 of this report. 2.7 Core Requirement #7: Financial Guarantees Liability Refer to Section 9.0 of this report. 2.8 Core Requirement #8: Water Quality The project qualifies for a Surface Area Exemption from the requirement to provide a water quality facility per Core Requirement #8. Refer to Section 4.6 of this report for further discussion. 2.9 Core Requirement #9: On-site BMPs Adherence to Core Requirement #9 is further discussed in Section 4.0 of this report. Per the 2017 City of Renton Surface Water Design Manual the project is subject to Core Requirement # 9. On-site BMPs and POWER ENGINEERS, INC. PAGE 6 the LID performance standard are infeasible at this site due to soil characteristics and size constraints. Refer to section 4.4.2 for discussion. 3.0 OFFSITE ANALYSIS 3.1 Level 1 Analysis A downstream analysis was completed by HDR for the project site in April, 2017 and can be found in Appendix H. The results of the previous analysis including field inspections indicate that no conveyance, flooding or erosion issues have been identified within ¼-mile of the project site. A second analysis was completed by POWER Engineers, Inc. for the CLR expansion in September, 2018 yielding the same conclusion. Results of the most recent Level 1 analysis including mapping can be found in Appendix C. 3.1.1 Tasks 1-5 Task 1 – Study Area The Study Area includes an approximate one-quarter mile stretch of downstream conveyance which receives the discharge from the existing detention pond. Task 2 – Resource Review • The following are noted: o Adopted basins plans were not available o The project site is not located within a FEMA flood hazard area o The project area is located inside a Coal Mine Hazard Area and is adjacent to an Erosion Hazard Area o The closest high-risk erosion hazard is approximately 1,400 feet west/southwest of the site o The closest high-hazard landslide area is approximately 2,000 feet west of the site o The project does not discharge to any erosion or landslide hazard areas o The nearest drainage complaints were three-quarters of a mile west of the project area and will not be impacted o No wetlands or impaired waters exist within one mile (downstream) of the site o No groundwater has been encountered o No stormwater quality problems exist within the study area o No Basin Plans, Basin Reconnaissance Summary Reports and no nearby offsite analysis reports were obtained POWER ENGINEERS, INC. PAGE 7 Task 3 through Task 5 – Field Inspection and Results The field inspection was conducted on September 18, 2018 under clear skies and in dry weather conditions. The existing conditions within the study area were observed in order to note any erosion or sedimentation, evidence of recurrent flooding, existing drainage issues and existing site conditions. Appendix C contains the 2018 site photos and study area map. The study area consists primarily of undeveloped land with ground cover consisting of grass and shrub vegetation. There is a residential area approximately 400-feet (downstream) from the pond discharge location which is separated from the site by a park. South of the park is a bike trail and forested area which contains a stream channel. The channel is noted to flow beneath the trail in a drainage culvert prior to terminating inside a grassy area to the southwest where flows appear to convert to overland flow. No erosion problems were noted at this location. The September 2018 field inspection noted no conveyance, flooding or erosion problems downstream of the site within one-quarter-mile of the pond discharge. The Level 1 Analysis has been deemed enough without further study of the area. 3.2 Level 2 Analysis Offsite drainage area characteristics and downstream conditions have been inspected. No issues were noted. As a result, the Level 2 Analysis is not required for the proposed expansion and access road. POWER ENGINEERS, INC. PAGE 8 FIGURE 5 DRAINAGE REVIEW FLOW CHART POWER ENGINEERS, INC. PAGE 9 4.0 FLOW CONTROL, LOW IMPACT DEVELOPMENT (LID) AND WATER QUALITY FACILITY ANALYSIS AND DESIGN 4.1 Calculation Assumptions and Parameters Calculations for this report include the following Assumptions: • For purposes of analyzing compliance with the LID Performance Standard and Flow Control Duration Standard the existing conditions have been modeled as the historical site conditions; assumed to consist of 0.56 acres of forested open space Calculations for this report were completed using the following parameters: • Regulatory requirements are from the City Surface Water Design Manual, City of Renton Public Works Department Surface Water Utility, December 12, 2016 • Hydrologic and Hydraulic modeling for this report were completed using the Western Washington Hydrology Model; 2012 (WWHM) • The land surface cover characteristics are summarized in Table 1 • Reduced Impervious Surface Credit: Impervious surfaces have been restricted to the maximum extent feasible. Permeable yard rock is being used where vehicle access is not required within the substation fence • Soil parameters are from the project Geotechnical Report (Appendix F) and the USDA Web Soil Survey • Substation ‘Pad Gravel’ is modeled as ‘Gravel/Dirt Roads and Parking Lots, Roads without Collection System’ using an effective impervious fraction of 0.50 per Table 3.2.2.D of the King County Surface Water Design Manual. POWER ENGINEERS, INC. PAGE 10 TABLE 1 LAND COVER SURFACES PRE-DEVELOPED LAND COVER ACRES PCT. IMPERVIOUS IMPERVIOUS ACRES PERVIOUS ACRES FOREST 0.56 0% 0.00 0.56 0.56 0.00 0.56 POST-DEVELOPED LAND COVER ACRES PCT. IMPERVIOUS IMPERVIOUS ACRES PERVIOUS ACRES ROAD GRAVEL 0.19 100% 0.19 0.00 PAD GRAVEL 0.29 50% 0.15 0.14 CONCRETE 0.08 100% 0.08 0.00 0.56 0.42 0.14 4.2 Pre-Developed Site Hydrology (Part A) The existing site features an existing substation and access road to the south that convey runoff to a 5,720 square foot (bottom area) detention pond with two-to-one (2:1, H:V) side slopes. The existing pond has a primary flow control structure with a flat top weir and three orifice openings on a 12” riser and an emergency overflow structure. The pond was designed in 2016 for adherence to the City of Renton’s Area-Specific Flow Control Facility. The existing substation runoff is captured in catch basins and conveyed to the existing detention pond which sits immediately south of the existing substation. Surface runoff from the areas peripheral to the existing substation also drain southward. The site for the expansion area drains primarily to the south and south west as well. The area consists of scrub and gravel with evidence of prior clearing. Existing trees that do remain are located to the south of the expansion area and will be maintained. The pre-developed drainage area characteristics are summarized in Table 2. WWHM results can be found in Appendix B. POWER ENGINEERS, INC. PAGE 11 TABLE 2 HISTORIC HYDROLOGICAL CHARACTERISTICS C FOREST, MODERATE – 0.56 ACRES RETURN PERIOD FLOW (CFS)1 2-Year 0.022 5-Year 0.036 10-Year 0.045 25-Year 0.056 50-Year 0.064 100-Year 0.070 Table Notes: 1 Assume no flow control/mitigation 4.3 Developed Site Hydrology (Part B) The developed site hydrology includes the addition of 0.56 acres of converted surface to the expansion area. Figure 5 in Appendix B depicts the developed site. The developed conditions were entered into the Mitigated Scenario within the WWHM model, using the existing pond geometry with modified flow controls to determine the developed runoff durations. Following attenuation in the existing pond, stormwater will discharge to the natural location southwest of the site. The existing pond has adequate capacity to receive the discharge from converted surfaces; 0.56 acres has been added to the existing pond in the pre-developed and mitigated scenarios to estimate the additional flow to the existing pond. The updated pond model for the existing pond can be found in Appendix B. TABLE 3 DEVELOPED HYDROLOGICAL CHARACTERISTICS C LAWN, FLAT – 0.14 ACRES DRIVEWAYS FLAT – 0.42 ACRES TOTAL AREA – 0.56 ACRES RETURN PERIOD FLOW (CFS)1 2-Year 0.012 5-Year 0.016 10-Year 0.018 25-Year 0.022 50-Year 0.024 100-Year 0.027 Table Notes: 1 Assumes mitigation from flow control in the existing detention pond POWER ENGINEERS, INC. PAGE 12 4.4 Performance Standards (Part C) 4.4.1 Area-Specific Flow Control Facility Standard The project is subject to the Flow Control Duration Standard – Matching Forested site conditions for areas draining to streams that are subject to flow-related water quality problems such as erosion and sedimentation. Applying the Area-Specific Flow Control Facility Requirements 1. The project does not qualify for the Direct Discharge Exemption 2. The project is in a designated flow control area and is subject to the Flow Control Duration Standard for forested conditions 3. Results from the WWHM are found in Appendix B. The Point of Compliance (POC) was analyzed for flow duration mitigation with the Low Flow Threshold at 50% of 2-year and the High Flow Threshold at the 50-year flow rate 4. There are no known downstream drainage problems at the project area 4.4.2 Low Impact Development Performance Standard Per Section 1.2.9.1 of the SWDM, projects that are subject to Core Requirement #9 must apply on-site BMPs to either supplement the flow mitigation provided by required flow control facilities or provide flow mitigation where flow control facilities are not required. Projects may opt to use the LID Performance Standard in lieu of the BMP selection and application requirements. Using the LID Performance Standard in WWHM, we estimate a 475’ x 475’ x 6’ deep detention pond would be required. Therefore, meeting the LID Performance Standard at this site is infeasible due to the lack of available space onsite. Applying the On-Site BMPs 1. The project site can be classified as a single Large Lot (>22,000 square feet) 2. The project expansion site is 0.56 acres and includes 0.42 acres of new impervious cover 3. Full Dispersion of target impervious surfaces is not feasible at the site due to the lack of native vegetated surface. The site contains less than 0.42 acres of native vegetated surface. The project proposes 0.42 acres of new impervious surface. The new impervious surface is greater than 100% of the total area of native vegetate surface on site 4. Due to size constraints, topography, and soil conditions the site is not suitable for Full Infiltration. Geotechnical Borings at the project site indicate the presence of shallow, medium dense to very dense glacial till underlaying the expansion area to depths of 20-feet 5. Basic Dispersion has been deemed infeasible at the site. 50% of site impervious equals 9,148 square feet. Each Basic Dispersion device can treat approximately 700 square feet of impervious surface and requires a minimum 25-foot downstream vegetated flow path segment. Treating the required impervious cover with Basic Dispersion will require approximately 13 separate Basic Dispersion devices. The site is not large enough to include adequate Basic Dispersion and the required vegetated flow path segments POWER ENGINEERS, INC. PAGE 13 6. Geotechnical analysis completed in January 2019 has deemed Limited Infiltration to be infeasible due to the presence of shallow, medium dense to very dense glacial till underlying the expansion area 7. The onsite soils are not conducive to infiltration making Bioretention subject to failure on site 8. Permeable Pavement is not feasible due to the lack of infiltrative soils. 4.5 Flow Control System (Part D) The existing pond is located at the southeast corner of the site, is “L” shaped, and has a bottom area of 5,720 square feet. Side slopes are 2:1 on the north, south and east sides and approximately 7:1 on the west side for access. Flow is controlled in a concrete drainage inlet structure containing a 12-inch PVC riser with three separate orifice openings. The existing pond depth is 11.8-feet with a crest elevation of 437.30’ This provides approximately 3.43-feet of freeboard from the new 100-year water surface elevation of 433.87’. To control flow for the new CLR expansion project, the existing control structure will be modified as follows: • The existing 7-foot riser will be replaced with an 8.5’ riser. • A 0.9-inch orifice will be added at the bottom of the riser. • A 2.3-inch orifice will be added at 6.4-feet above the bottom of the riser. • A 1.6-inch orifice will be added at 7.3-feet above the bottom of the riser. 4.6 Water Quality System (Part E) The proposed expansion and access road will not be used for manufacture, storage, or transport of erodible or leachable materials, wastes or chemicals. The areas will not be used for parking and will only be subject to vehicular traffic on an as-needed basis for maintenance of the CLR components. The project will not create vegetative surfaces that will require fertilization. The expansion project will not contribute any new Pollution Generating Impervious Surface (PGIS) or Pollution Generating Pervious Surface (PGPS) since the proposed land cover does not meet the definition of a pollution generating surface. The surfaces qualify as infrequently used maintenance roads as defined by the Department of Ecology, see below. As a result the project qualifies for the Surface Area Exemption from the requirement to provide a water quality facility per Core Requirement #8. Additionally the Department of Ecology (DOE) in Volume 5 page 4-3 identifies infrequently used maintenance roads are exempt from treatment as they are not regularly used. Below is the definition of Vehicular Use from the DOE manual. Vehicular Use: Regular use of an impervious or pervious surface by motor vehicles. The following are subject to regular vehicle use: roads, unvegetated road shoulders, bike lanes within the traveled lane of a roadway, driveways, parking lots, unrestricted access fire lanes, vehicular equipment storage yards, and airport runways. The following are not considered subject to regular vehicle use: paved bicycle pathways separated from and not subject to drainage from roads for motor vehicles, restricted access fire lanes, and infrequently used maintenance access roads. POWER ENGINEERS, INC. PAGE 14 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN The 100-year peak flow for the entire site as calculated with AutoDesk Storm and Sanitary Analysis software. The 100-year peak flow was calculated at 1.0 cfs. Therefore, the proposed conveyance channel has a flow capacity of 2.0 cfs and has sufficient capacity to convey the full 100-year peak flow. Design analysis of the existing conveyance system can be found in Appendix H. 6.0 SPECIAL REPORTS AND STUDIES No special reports or studies have been prepared for this project. 7.0 OTHER PERMITS Additional permitting is not anticipated to affect the stormwater design. 8.0 CSWPP PLAN ANALYSIS AND DESIGN The CSWPPP for the CLR expansion can be found in Appendix G. Project construction TESC plans will be implemented for the expansion. The TESC plans and CSWPPP will be used to direct the placement of temporary erosion and sediment control measures to be implemented during construction which will include; catch basin sediment control, silt fence, dedicated construction entrance, high visibility safety fence and concrete washout facilities. 9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT Bond quantities and the Facility Summary can be found in Appendix E of this report. A Declaration of Covenant is not required for this pond as it is a privately maintained flow control facility. 10.0 OPERATIONS AND MAINTENANCE MANUAL The operation and maintenance requirements for the existing facility can be found in Appendix D 11.0 REFERENCES City of Renton Public Works Department Surface Water Utility. Surface Water Design Manual. December 12, 2016 King County, Washington. Surface Water Design Manual. April 24, 2016 POWER ENGINEERS, INC. APPENDIX A TIR WORKSHEET CITY OF RENTON SURFACE WATER DESIGN MANUAL 2017 City of Renton Surface Water Design Manual 12/12/2016 8-A-1 REFERENCE 8-A TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner _____________________________ Phone ___________________________________ Address __________________________________ _________________________________________ Project Engineer ___________________________ Company _________________________________ Phone ___________________________________ Project Name __________________________ CED Permit # ________________________ Location Township ________________ Range __________________ Section _________________ Site Address __________________________ _____________________________________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS Land Use (e.g., Subdivision / Short Subd.) Building (e.g., M/F / Commercial / SFR) Grading Right-of-Way Use Other _______________________ DFW HPA COE 404 DOE Dam Safety FEMA Floodplain COE Wetlands Other ________ Shoreline Management Structural Rockery/Vault/_____ ESA Section 7 Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review (check one): Date (include revision dates): Date of Final: Full Targeted Simplified Large Project Directed ____________________________________ __________________ Plan Type (check one): Date (include revision dates): Date of Final: Full Modified Simplified ____________________________________ __________________ REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-2 Part 6 SWDM ADJUSTMENT APPROVALS Type (circle one): Standard / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Approved Adjustment No. ______________________ Date of Approval: _______________________ Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ Re: SWDM Adjustment No. ________________ Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan: ____________________________________________________________________ Special District Overlays: ______________________________________________________________ Drainage Basin: _____________________________________________________________________ Stormwater Requirements: _____________________________________________________________ Part 9 ONSITE AND ADJACENT SENSITIVE AREAS River/Stream ________________________ Lake ______________________________ Wetlands ____________________________ Closed Depression ____________________ Floodplain ___________________________ Other _______________________________ _______________________________ Steep Slope __________________________ Erosion Hazard _______________________ Landslide Hazard ______________________ Coal Mine Hazard ______________________ Seismic Hazard _______________________ Habitat Protection ______________________ _____________________________________ REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-3 Part 10 SOILS Soil Type ______________________ ______________________ ______________________ ______________________ Slopes ________________________ ________________________ ________________________ ________________________ Erosion Potential _________________________ _________________________ _________________________ _________________________ High Groundwater Table (within 5 feet) Other ________________________________ Sole Source Aquifer Seeps/Springs Additional Sheets Attached Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE Core 2 – Offsite Analysis_________________ Sensitive/Critical Areas__________________ SEPA________________________________ LID Infeasibility________________________ Other________________________________ _____________________________________ LIMITATION / SITE CONSTRAINT _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________ Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Core Requirements (all 8 apply): Discharge at Natural Location Number of Natural Discharge Locations: Offsite Analysis Level: 1 / 2 / 3 dated:__________________ Flow Control (include facility summary sheet) Standard: _______________________________ or Exemption Number: ____________ On-site BMPs: _______________________________ Conveyance System Spill containment located at: _____________________________ Erosion and Sediment Control / Construction Stormwater Pollution Prevention CSWPP/CESCL/ESC Site Supervisor: _____________________ Contact Phone: _________________________ After Hours Phone: _________________________ REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-4 Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Maintenance and Operation Responsibility (circle one): Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No Water Quality (include facility summary sheet) Type (circle one): Basic / Sens. Lake / Enhanced Basic / Bog or Exemption No. _______________________ Special Requirements (as applicable): Area Specific Drainage Requirements Type: SDO / MDP / BP / Shared Fac. / None Name: ________________________ Floodplain/Floodway Delineation Type (circle one): Major / Minor / Exemption / None 100-year Base Flood Elevation (or range): _______________ Datum: Flood Protection Facilities Describe: Source Control (commercial / industrial land use) Describe land use: Describe any structural controls: Oil Control High-Use Site: Yes / No Treatment BMP: _________________________________ Maintenance Agreement: Yes / No with whom? _____________________________________ Other Drainage Structures Describe: REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-5 Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Clearing Limits Cover Measures Perimeter Protection Traffic Area Stabilization Sediment Retention Surface Water Collection Dewatering Control Dust Control Flow Control Control Pollutants Protect Existing and Proposed BMPs/Facilities Maintain Protective BMPs / Manage Project MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION Stabilize exposed surfaces Remove and restore Temporary ESC Facilities Clean and remove all silt and debris, ensure operation of Permanent BMPs/Facilities, restore operation of BMPs/Facilities as necessary Flag limits of sensitive areas and open space preservation areas Other _______________________ Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description Detention Infiltration Regional Facility Shared Facility On-site BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ Vegetated Flowpath Wetpool Filtration Oil Control Spill Control On-site BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS Drainage Easement Covenant Native Growth Protection Covenant Tract Other ____________________________ Cast in Place Vault Retaining Wall Rockery > 4′ High Structural on Steep Slope Other _______________________________ REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-6 Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information provided here is accurate. ____________________________________________________________________________________ Signed/Date POWER ENGINEERS, INC. APPENDIX B WWHM (2012) MODEL RESULTS POWER ENGINEERS, INC. FIGURE 6 DEVELOPED HYDROLOGY AND MITIGATION PLAN EXISTINGSUBSTATIONPADEX. PONDNEW CLR AREAEXISTING ACCESS ROADEXPANSION AREA (0.56 ACRES)EXISTING SUBSTATION AREA (TYP.)OP OP OP OP OPOP OPOPOPOPOP OP OP OP OP OP T T TT TT T TOP OP OP OP OP OP OP OP OP OP OP OP EX. UNDERGROUNDTELECOM. AT EL. 437.5±LEGEND:PROPOSED PAD GRAVEL SURFACEPROPOSED ROAD GRAVEL SURFACEPROPOSED CONCRETE PADRAISE TO 434.0018"USE WATER TIGHT COUPLINGTO EXTEND EXISTING 18-INCHDIAMETER PVC RISER 12"18" CONCRETE RISERON EXISTING TYPE 2CATCH BASINSTRUCTURE (TYP.)GRANTED.THIS DRAWING WAS PREPARED BY POWERENGINEERS, INC. FOR A SPECIFIC PROJECT,TAKING INTO CONSIDERATION THE SPECIFICAND UNIQUE REQUIREMENTS OF THE PROJECT.REUSE OF THIS DRAWING OR ANY INFORMATIONCONTAINED IN THIS DRAWING FOR ANY PURPOSEIS PROHIBITED UNLESS WRITTEN PERMISSIONFROM BOTH POWER AND POWER'S CLIENT IS12FOR 11x17 DWG ONLYREFERENCE DRAWINGSCKDAPPDDSGNDRNDATEREVREVISIONSDSGNCKDSCALE:DRNDRAWING NUMBERREVJOB NUMBERDCB34576A8PUDGET SOUND ENERGYTALBOT HILL CLR INSTALLATION150680FIGURE 6DEVELOPED HYDROLOGYSMTSMTHAL03/2019ISSUED FOR PERMIT01" = 40'03/201903/20191" = 40'4012080020FEET WWHM2012 PROJECT REPORT Existing Pond 3/21/2019 1:19:15 PM Page 2 General Model Information Project Name:Existing Pond Site Name:Talbot Hill CLR Addition Site Address:2400 S Puget Dr City:Renton Report Date:3/21/2019 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2018/10/10 Version:4.2.16 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year Existing Pond 3/21/2019 1:19:15 PM Page 3 Landuse Basin Data Predeveloped Land Use Existing Site Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 5.89 Pervious Total 5.89 Impervious Land Use acre Impervious Total 0 Basin Total 5.89 Element Flows To: Surface Interflow Groundwater Existing Pond 3/21/2019 1:19:15 PM Page 4 CLR Addition Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 0.56 Pervious Total 0.56 Impervious Land Use acre Impervious Total 0 Basin Total 0.56 Element Flows To: Surface Interflow Groundwater Existing Pond 3/21/2019 1:19:15 PM Page 5 Mitigated Land Use Existing Site Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 2.06 Pervious Total 2.06 Impervious Land Use acre PARKING FLAT 3.83 Impervious Total 3.83 Basin Total 5.89 Element Flows To: Surface Interflow Groundwater Existing Pond Existing Pond Existing Pond 3/21/2019 1:19:15 PM Page 6 CLR Addition Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.14 Pervious Total 0.14 Impervious Land Use acre PARKING FLAT 0.42 Impervious Total 0.42 Basin Total 0.56 Element Flows To: Surface Interflow Groundwater Existing Pond Existing Pond Existing Pond 3/21/2019 1:19:15 PM Page 7 Routing Elements Predeveloped Routing Existing Pond 3/21/2019 1:19:15 PM Page 8 Mitigated Routing Existing Pond Bottom Length:211.85 ft. Bottom Width:27.00 ft. Depth:9 ft. Volume at riser head:3.0148 acre-feet. Side slope 1:7 To 1 Side slope 2:2 To 1 Side slope 3:2 To 1 Side slope 4:2 To 1 Discharge Structure Riser Height:8.5 ft. Riser Diameter:12 in. Orifice 1 Diameter:0.9 in.Elevation:0 ft. Orifice 2 Diameter:2.3 in.Elevation:6.4 ft. Orifice 3 Diameter:1.6 in.Elevation:7.3 ft. Element Flows To: Outlet 1 Outlet 2 Pond Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 425.50 0.131 0.000 0.000 0.000 425.60 0.135 0.013 0.007 0.000 425.70 0.140 0.027 0.009 0.000 425.80 0.145 0.041 0.012 0.000 425.90 0.149 0.056 0.013 0.000 426.00 0.154 0.071 0.015 0.000 426.10 0.159 0.087 0.017 0.000 426.20 0.164 0.103 0.018 0.000 426.30 0.168 0.120 0.019 0.000 426.40 0.173 0.137 0.020 0.000 426.50 0.178 0.154 0.022 0.000 426.60 0.183 0.172 0.023 0.000 426.70 0.188 0.191 0.024 0.000 426.80 0.192 0.210 0.025 0.000 426.90 0.197 0.229 0.026 0.000 427.00 0.202 0.249 0.026 0.000 427.10 0.207 0.270 0.027 0.000 427.20 0.212 0.291 0.028 0.000 427.30 0.217 0.312 0.029 0.000 427.40 0.222 0.334 0.030 0.000 427.50 0.227 0.357 0.031 0.000 427.60 0.232 0.380 0.031 0.000 427.70 0.237 0.403 0.032 0.000 427.80 0.242 0.427 0.033 0.000 427.90 0.247 0.452 0.034 0.000 428.00 0.252 0.477 0.034 0.000 428.10 0.257 0.502 0.035 0.000 428.20 0.262 0.528 0.036 0.000 428.30 0.267 0.555 0.036 0.000 428.40 0.272 0.582 0.037 0.000 428.50 0.277 0.609 0.038 0.000 428.60 0.282 0.637 0.038 0.000 428.70 0.287 0.666 0.039 0.000 Existing Pond 3/21/2019 1:19:15 PM Page 9 428.80 0.292 0.695 0.039 0.000 428.90 0.298 0.724 0.040 0.000 429.00 0.303 0.754 0.041 0.000 429.10 0.308 0.785 0.041 0.000 429.20 0.313 0.816 0.042 0.000 429.30 0.319 0.848 0.042 0.000 429.40 0.324 0.880 0.043 0.000 429.50 0.329 0.912 0.044 0.000 429.60 0.334 0.946 0.044 0.000 429.70 0.340 0.979 0.045 0.000 429.80 0.345 1.014 0.045 0.000 429.90 0.350 1.048 0.046 0.000 430.00 0.356 1.084 0.046 0.000 430.10 0.361 1.120 0.047 0.000 430.20 0.366 1.156 0.047 0.000 430.30 0.372 1.193 0.048 0.000 430.40 0.377 1.231 0.048 0.000 430.50 0.383 1.269 0.049 0.000 430.60 0.388 1.307 0.049 0.000 430.70 0.394 1.346 0.050 0.000 430.80 0.399 1.386 0.050 0.000 430.90 0.405 1.426 0.051 0.000 431.00 0.410 1.467 0.051 0.000 431.10 0.416 1.508 0.052 0.000 431.20 0.421 1.550 0.052 0.000 431.30 0.427 1.593 0.052 0.000 431.40 0.433 1.636 0.053 0.000 431.50 0.438 1.679 0.053 0.000 431.60 0.444 1.724 0.054 0.000 431.70 0.449 1.768 0.054 0.000 431.80 0.455 1.814 0.055 0.000 431.90 0.461 1.859 0.055 0.000 432.00 0.466 1.906 0.101 0.000 432.10 0.472 1.953 0.120 0.000 432.20 0.478 2.000 0.135 0.000 432.30 0.484 2.048 0.148 0.000 432.40 0.489 2.097 0.159 0.000 432.50 0.495 2.146 0.169 0.000 432.60 0.501 2.196 0.178 0.000 432.70 0.507 2.247 0.187 0.000 432.80 0.513 2.298 0.195 0.000 432.90 0.518 2.349 0.225 0.000 433.00 0.524 2.401 0.241 0.000 433.10 0.530 2.454 0.255 0.000 433.20 0.536 2.508 0.268 0.000 433.30 0.542 2.561 0.280 0.000 433.40 0.548 2.616 0.291 0.000 433.50 0.554 2.671 0.301 0.000 433.60 0.560 2.727 0.311 0.000 433.70 0.566 2.783 0.321 0.000 433.80 0.572 2.840 0.330 0.000 433.90 0.578 2.898 0.339 0.000 434.00 0.584 2.956 0.348 0.000 434.10 0.590 3.014 0.690 0.000 434.20 0.596 3.074 1.272 0.000 434.30 0.602 3.134 1.882 0.000 434.40 0.608 3.194 2.340 0.000 434.50 0.614 3.255 2.591 0.000 Existing Pond 3/21/2019 1:19:15 PM Page 10 434.60 0.620 3.317 2.835 0.000 Existing Pond 3/21/2019 1:19:15 PM Page 11 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:6.45 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:2.2 Total Impervious Area:4.25 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.19205 5 year 0.314691 10 year 0.393547 25 year 0.487349 50 year 0.552323 100 year 0.613011 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.09782 5 year 0.171276 10 year 0.230977 25 year 0.319242 50 year 0.394504 100 year 0.478089 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.221 0.050 1950 0.262 0.162 1951 0.420 0.343 1952 0.132 0.047 1953 0.106 0.145 1954 0.163 0.114 1955 0.261 0.051 1956 0.210 0.207 1957 0.170 0.054 1958 0.188 0.076 Existing Pond 3/21/2019 1:20:08 PM Page 12 1959 0.162 0.115 1960 0.290 0.163 1961 0.159 0.174 1962 0.099 0.047 1963 0.136 0.103 1964 0.193 0.163 1965 0.128 0.147 1966 0.123 0.100 1967 0.295 0.165 1968 0.166 0.052 1969 0.162 0.055 1970 0.130 0.124 1971 0.146 0.054 1972 0.319 0.273 1973 0.141 0.150 1974 0.156 0.135 1975 0.218 0.053 1976 0.156 0.054 1977 0.023 0.043 1978 0.132 0.098 1979 0.080 0.043 1980 0.375 0.243 1981 0.118 0.054 1982 0.243 0.123 1983 0.208 0.112 1984 0.125 0.050 1985 0.074 0.048 1986 0.329 0.055 1987 0.290 0.148 1988 0.115 0.050 1989 0.076 0.051 1990 0.695 0.164 1991 0.369 0.289 1992 0.151 0.055 1993 0.147 0.044 1994 0.049 0.043 1995 0.211 0.162 1996 0.487 0.317 1997 0.376 0.279 1998 0.092 0.052 1999 0.412 0.234 2000 0.146 0.080 2001 0.026 0.037 2002 0.170 0.171 2003 0.253 0.051 2004 0.271 0.182 2005 0.201 0.048 2006 0.226 0.189 2007 0.526 0.273 2008 0.641 0.180 2009 0.299 0.097 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.6954 0.3428 2 0.6407 0.3172 3 0.5256 0.2891 Existing Pond 3/21/2019 1:20:08 PM Page 13 4 0.4870 0.2791 5 0.4196 0.2731 6 0.4121 0.2731 7 0.3758 0.2432 8 0.3750 0.2341 9 0.3689 0.2071 10 0.3291 0.1885 11 0.3185 0.1821 12 0.2987 0.1803 13 0.2949 0.1737 14 0.2905 0.1712 15 0.2895 0.1653 16 0.2708 0.1642 17 0.2624 0.1634 18 0.2610 0.1628 19 0.2534 0.1625 20 0.2432 0.1617 21 0.2260 0.1497 22 0.2210 0.1485 23 0.2178 0.1471 24 0.2107 0.1450 25 0.2103 0.1348 26 0.2080 0.1239 27 0.2009 0.1233 28 0.1929 0.1153 29 0.1885 0.1136 30 0.1697 0.1123 31 0.1697 0.1033 32 0.1660 0.0998 33 0.1634 0.0983 34 0.1616 0.0965 35 0.1616 0.0802 36 0.1592 0.0759 37 0.1565 0.0554 38 0.1557 0.0552 39 0.1506 0.0545 40 0.1470 0.0540 41 0.1464 0.0538 42 0.1464 0.0536 43 0.1412 0.0536 44 0.1360 0.0530 45 0.1317 0.0524 46 0.1315 0.0515 47 0.1297 0.0512 48 0.1282 0.0511 49 0.1253 0.0505 50 0.1232 0.0505 51 0.1177 0.0505 52 0.1147 0.0503 53 0.1064 0.0485 54 0.0991 0.0479 55 0.0920 0.0469 56 0.0796 0.0468 57 0.0759 0.0444 58 0.0744 0.0432 59 0.0494 0.0429 60 0.0263 0.0425 61 0.0228 0.0366 Existing Pond 3/21/2019 1:20:08 PM Page 14 Existing Pond 3/21/2019 1:20:08 PM Page 15 Duration Flows The Facility PASSED Flow(cfs)Predev Mit Percentage Pass/Fail 0.0960 17085 15278 89 Pass 0.1006 15682 14713 93 Pass 0.1052 14125 13629 96 Pass 0.1099 13019 12649 97 Pass 0.1145 11689 11593 99 Pass 0.1191 10530 10515 99 Pass 0.1237 9693 9623 99 Pass 0.1283 8806 8722 99 Pass 0.1329 8173 8046 98 Pass 0.1375 7420 7219 97 Pass 0.1421 6748 6400 94 Pass 0.1467 6265 5734 91 Pass 0.1513 5764 5058 87 Pass 0.1559 5390 4590 85 Pass 0.1606 4966 3993 80 Pass 0.1652 4579 3399 74 Pass 0.1698 4286 3018 70 Pass 0.1744 3968 2588 65 Pass 0.1790 3709 2340 63 Pass 0.1836 3420 2033 59 Pass 0.1882 3142 1800 57 Pass 0.1928 2954 1573 53 Pass 0.1974 2723 1375 50 Pass 0.2020 2490 1313 52 Pass 0.2066 2346 1251 53 Pass 0.2113 2143 1191 55 Pass 0.2159 2004 1155 57 Pass 0.2205 1838 1103 60 Pass 0.2251 1704 1054 61 Pass 0.2297 1594 987 61 Pass 0.2343 1447 925 63 Pass 0.2389 1346 882 65 Pass 0.2435 1243 793 63 Pass 0.2481 1148 715 62 Pass 0.2527 1094 674 61 Pass 0.2573 1023 616 60 Pass 0.2620 966 563 58 Pass 0.2666 892 509 57 Pass 0.2712 827 384 46 Pass 0.2758 776 329 42 Pass 0.2804 726 286 39 Pass 0.2850 684 265 38 Pass 0.2896 633 231 36 Pass 0.2942 590 205 34 Pass 0.2988 560 189 33 Pass 0.3034 507 165 32 Pass 0.3080 469 131 27 Pass 0.3127 431 104 24 Pass 0.3173 389 72 18 Pass 0.3219 359 60 16 Pass 0.3265 329 50 15 Pass 0.3311 298 37 12 Pass 0.3357 273 28 10 Pass Existing Pond 3/21/2019 1:20:08 PM Page 16 0.3403 242 15 6 Pass 0.3449 223 0 0 Pass 0.3495 199 0 0 Pass 0.3541 175 0 0 Pass 0.3587 155 0 0 Pass 0.3634 131 0 0 Pass 0.3680 121 0 0 Pass 0.3726 107 0 0 Pass 0.3772 95 0 0 Pass 0.3818 85 0 0 Pass 0.3864 75 0 0 Pass 0.3910 69 0 0 Pass 0.3956 62 0 0 Pass 0.4002 54 0 0 Pass 0.4048 47 0 0 Pass 0.4094 39 0 0 Pass 0.4141 29 0 0 Pass 0.4187 25 0 0 Pass 0.4233 22 0 0 Pass 0.4279 20 0 0 Pass 0.4325 18 0 0 Pass 0.4371 14 0 0 Pass 0.4417 13 0 0 Pass 0.4463 9 0 0 Pass 0.4509 7 0 0 Pass 0.4555 7 0 0 Pass 0.4601 7 0 0 Pass 0.4648 6 0 0 Pass 0.4694 6 0 0 Pass 0.4740 6 0 0 Pass 0.4786 6 0 0 Pass 0.4832 6 0 0 Pass 0.4878 6 0 0 Pass 0.4924 5 0 0 Pass 0.4970 5 0 0 Pass 0.5016 5 0 0 Pass 0.5062 5 0 0 Pass 0.5108 5 0 0 Pass 0.5155 5 0 0 Pass 0.5201 4 0 0 Pass 0.5247 4 0 0 Pass 0.5293 3 0 0 Pass 0.5339 3 0 0 Pass 0.5385 3 0 0 Pass 0.5431 3 0 0 Pass 0.5477 3 0 0 Pass 0.5523 3 0 0 Pass Existing Pond 3/21/2019 1:20:08 PM Page 17 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0 acre-feet On-line facility target flow:0 cfs. Adjusted for 15 min:0 cfs. Off-line facility target flow:0 cfs. Adjusted for 15 min:0 cfs. Existing Pond 3/21/2019 1:20:08 PM Page 18 LID Report Existing Pond 3/21/2019 1:20:46 PM Page 19 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. Existing Pond 3/21/2019 1:20:46 PM Page 20 Appendix Predeveloped Schematic Existing Pond 3/21/2019 1:20:50 PM Page 21 Mitigated Schematic Existing Pond 3/21/2019 1:20:55 PM Page 22 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 Existing Pond.wdm MESSU 25 PreExisting Pond.MES 27 PreExisting Pond.L61 28 PreExisting Pond.L62 30 POCExisting Pond1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 11 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Existing Site MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 11 C, Forest, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 11 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 11 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO Existing Pond 3/21/2019 1:20:55 PM Page 23 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 11 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 11 0 4.5 0.08 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 11 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 11 0.2 0.5 0.35 6 0.5 0.7 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 11 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATE1 Existing Pond 3/21/2019 1:20:55 PM Page 24 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Existing Site*** PERLND 11 5.89 COPY 501 12 PERLND 11 5.89 COPY 501 13 CLR Addition*** PERLND 11 0.56 COPY 501 12 PERLND 11 0.56 COPY 501 13 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** Existing Pond 3/21/2019 1:20:55 PM Page 25 <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 END MASS-LINK END RUN Existing Pond 3/21/2019 1:20:55 PM Page 26 Mitigated UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 Existing Pond.wdm MESSU 25 MitExisting Pond.MES 27 MitExisting Pond.L61 28 MitExisting Pond.L62 30 POCExisting Pond1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 16 IMPLND 11 RCHRES 1 COPY 1 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Existing Pond MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 16 C, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 16 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* Existing Pond 3/21/2019 1:20:55 PM Page 27 16 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 16 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 16 0 4.5 0.03 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 16 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 16 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 16 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 11 PARKING/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 11 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 11 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 11 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 11 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** Existing Pond 3/21/2019 1:20:55 PM Page 28 # - # ***PETMAX PETMIN 11 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 11 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Existing Site*** PERLND 16 2.06 RCHRES 1 2 PERLND 16 2.06 RCHRES 1 3 IMPLND 11 3.83 RCHRES 1 5 CLR Addition*** PERLND 16 0.14 RCHRES 1 2 PERLND 16 0.14 RCHRES 1 3 IMPLND 11 0.42 RCHRES 1 5 ******Routing****** PERLND 16 2.06 COPY 1 12 IMPLND 11 3.83 COPY 1 15 PERLND 16 2.06 COPY 1 13 PERLND 16 0.14 COPY 1 12 IMPLND 11 0.42 COPY 1 15 PERLND 16 0.14 COPY 1 13 RCHRES 1 1 COPY 501 16 END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** 1 Existing Pond 1 1 1 1 28 0 1 END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** 1 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit Existing Pond 3/21/2019 1:20:55 PM Page 29 * * * * * * * * * * * * * * *** 1 0 1 0 0 4 0 0 0 0 0 0 0 0 0 2 2 2 2 2 END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** 1 1 0.04 0.0 425.5 0.5 0.0 END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES FTABLE 1 91 4 Depth Area Volume Outflow1 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (ft/sec) (Minutes)*** 0.000000 0.131312 0.000000 0.000000 0.100000 0.135945 0.013363 0.006951 0.200000 0.140595 0.027190 0.009830 0.300000 0.145261 0.041483 0.012039 0.400000 0.149944 0.056243 0.013902 0.500000 0.154644 0.071472 0.015543 0.600000 0.159360 0.087173 0.017026 0.700000 0.164092 0.103345 0.018390 0.800000 0.168841 0.119992 0.019660 0.900000 0.173606 0.137114 0.020853 1.000000 0.178388 0.154714 0.021981 1.100000 0.183187 0.172793 0.023054 1.200000 0.188002 0.191352 0.024079 1.300000 0.192834 0.210394 0.025062 1.400000 0.197682 0.229920 0.026008 1.500000 0.202546 0.249931 0.026921 1.600000 0.207428 0.270430 0.027804 1.700000 0.212325 0.291417 0.028659 1.800000 0.217240 0.312896 0.029490 1.900000 0.222170 0.334866 0.030298 2.000000 0.227118 0.357331 0.031086 2.100000 0.232082 0.380291 0.031853 2.200000 0.237062 0.403748 0.032603 2.300000 0.242059 0.427704 0.033336 2.400000 0.247072 0.452160 0.034053 2.500000 0.252102 0.477119 0.034755 2.600000 0.257149 0.502582 0.035443 2.700000 0.262212 0.528550 0.036118 2.800000 0.267291 0.555025 0.036781 2.900000 0.272387 0.582009 0.037432 3.000000 0.277500 0.609503 0.038072 3.100000 0.282629 0.637510 0.038701 3.200000 0.287775 0.666030 0.039320 3.300000 0.292937 0.695065 0.039930 3.400000 0.298116 0.724618 0.040531 3.500000 0.303311 0.754689 0.041122 3.600000 0.308523 0.785281 0.041706 3.700000 0.313751 0.816395 0.042281 3.800000 0.318996 0.848032 0.042848 3.900000 0.324257 0.880195 0.043409 4.000000 0.329535 0.912884 0.043962 4.100000 0.334830 0.946103 0.044508 4.200000 0.340140 0.979851 0.045047 4.300000 0.345468 1.014131 0.045580 4.400000 0.350812 1.048945 0.046107 Existing Pond 3/21/2019 1:20:55 PM Page 30 4.500000 0.356173 1.084295 0.046628 4.600000 0.361550 1.120181 0.047144 4.700000 0.366943 1.156605 0.047653 4.800000 0.372353 1.193570 0.048158 4.900000 0.377780 1.231077 0.048657 5.000000 0.383223 1.269127 0.049151 5.100000 0.388683 1.307722 0.049640 5.200000 0.394159 1.346864 0.050124 5.300000 0.399652 1.386555 0.050604 5.400000 0.405161 1.426796 0.051079 5.500000 0.410687 1.467588 0.051550 5.600000 0.416229 1.508934 0.052016 5.700000 0.421788 1.550835 0.052478 5.800000 0.427364 1.593292 0.052937 5.900000 0.432956 1.636308 0.053391 6.000000 0.438564 1.679884 0.053842 6.100000 0.444189 1.724022 0.054289 6.200000 0.449831 1.768723 0.054732 6.300000 0.455489 1.813989 0.055171 6.400000 0.461163 1.859821 0.055608 6.500000 0.466854 1.906222 0.101436 6.600000 0.472562 1.953193 0.120669 6.700000 0.478286 2.000736 0.135524 6.800000 0.484027 2.048851 0.148110 6.900000 0.489784 2.097542 0.159247 7.000000 0.495558 2.146809 0.169352 7.100000 0.501348 2.196654 0.178675 7.200000 0.507155 2.247079 0.187379 7.300000 0.512978 2.298086 0.195576 7.400000 0.518818 2.349676 0.225316 7.500000 0.524675 2.401850 0.241825 7.600000 0.530548 2.454612 0.255903 7.700000 0.536437 2.507961 0.268608 7.800000 0.542343 2.561900 0.280367 7.900000 0.548265 2.616430 0.291409 8.000000 0.554205 2.671554 0.301877 8.100000 0.560160 2.727272 0.311866 8.200000 0.566132 2.783587 0.321446 8.300000 0.572121 2.840499 0.330671 8.400000 0.578126 2.898012 0.339583 8.500000 0.584148 2.956125 0.348214 8.600000 0.590186 3.014842 0.690114 8.700000 0.596241 3.074163 1.272419 8.800000 0.602312 3.134091 1.882353 8.900000 0.608400 3.194626 2.340462 9.000000 0.614504 3.255772 2.591329 END FTABLE 1 END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1000 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1001 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** Existing Pond 3/21/2019 1:20:55 PM Page 31 <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 2 PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 2 MASS-LINK 3 PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 3 MASS-LINK 5 IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 5 MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 MASS-LINK 16 RCHRES ROFLOW COPY INPUT MEAN END MASS-LINK 16 END MASS-LINK END RUN Existing Pond 3/21/2019 1:20:55 PM Page 32 Predeveloped HSPF Message File Existing Pond 3/21/2019 1:20:56 PM Page 33 Mitigated HSPF Message File Existing Pond 3/21/2019 1:20:56 PM Page 34 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2019; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com POWER ENGINEERS, INC. APPENDIX C LEVEL 1 ANALYSIS OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE KING COUNTY SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT #2 Basin: Duwamish River Subbasin Name: Refer to the ‘Downstream Reach’ map in Appendix C Subbasin Number: 1 Date 03/26/2019 ood of problem, potential impacts 2016 Draft Surface Water Design Manual 4/24/2016 Symbol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from site discharge Existing Problems Potential Observations of field Problems inspector, resource reviewer, or resident see map Type: sheet flow, swale, stream, channel, pipe, pond, flow control/wq BMP; Size: diameter, surface area drainage basin, vegetation, cover, depth, type of sensitive area, volume % ¼ ml = 1,320 ft. constrictions, under capacity, ponding, tributary area, likelihood of problems overtopping, flooding, habitat or organism overflow pathways, potential impacts destruction, scouring, bank sloughing, sedimentation, incision, other erosion 1 Existing flow control 11.8’ deep pond N/A 209 ft. None None 2 Pond inlet pipe ~3’ of cover ~1% 127 ft. 3 Sheet flow Brush cover ~12% 255’ 4 Sheet flow Brush cover ~12% 255’ 5 Sheet flow Brush cover ~12% 255’ 6 Pond outlet pipe ~15’ of cover ~1% 261’ 7 Pond outlet pipe ~15’ of cover ~1% 261’ 8 Access Road Road gravel ~12% 325’ 9 Sheet flow Brush/grass cover ~2% 325’ 10 Sheet flow Brush/grass cover ~2% 500’ 11 Sheet flow Brush/grass cover ~2% 440’ 12 Sheet flow Brush/grass cover ~2% 520’ 13 Shallow Conc. Flow Brush/grass cover ~2% 520’ 14 Sheet flow Brush/grass cover ~2% 504’ 15 Sheet flow Brush/grass cover ~2% 670’ 16 Sheet flow Brush/grass cover ~2% ~ 1,340’ 1 2 3 4 5 6 7 8 9 10 11 12 13 141516 local depression at outlet location general flow direction PHOTO NO. 1 PHOTO NO. 2 PHOTO NO. 3 PHOTO NO. 4 PHOTO NO. 5 PHOTO NO. 6 PHOTO NO. 7 PHOTO NO. 8 PHOTO NO. 9 PHOTO NO. 10 PHOTO NO. 11 PHOTO NO. 12 PHOTO NO. 13 PHOTO NO. 14 PHOTO NO. 15 PHOTO NO. 16 POWER ENGINEERS, INC. APPENDIX D OPERATION AND MAINTENANCE CITY OF RENTON SURFACE WATER DESIGN MANUAL 2017 City of Renton Surface Water Design Manual 12/12/2016 A-1 APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS This appendix contains the maintenance requirements for the following typical stormwater flow control and water quality facilities and on-site BMPs (ctrl/click the title to follow the link): No. 1 – Detention Ponds No. 2 – Infiltration Facilities No. 3 – Detention Tanks and Vaults No. 4 – Control Structure/Flow Restrictor No. 5 – Catch Basins and Manholes No. 6 – Conveyance Pipes and Ditches No. 7 – Debris Barriers (e.g., trash racks) No. 8 – Energy Dissipaters No. 9 – Fencing No. 10 – Gates/Bollards/Access Barriers No. 11 – Grounds (landscaping) No. 12 – Access Roads No. 13 – Basic Bioswale (grass) No. 14 – Wet Bioswale No. 15 – Filter Strip No. 16 – Wetpond No. 17 – Wetvault No. 18 – Stormwater Wetland No. 19 – Sand Filter Pond No. 20 – Sand Filter Vault No. 21 – Proprietary Facility Cartridge Filter Systems No. 22 – Baffle Oil/Water Separator No. 23 – Coalescing Plate Oil/Water Separator APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-2 No. 24 – Catch Basin Insert (not allowed in the city for oil control) No. 25 – Drywell BMP No. 26 – Gravel Filled Infiltration Trench BMP No. 27 – Gravel Filled Dispersion Trench BMP No. 28 – Native Vegetated Surface/Native Vegetated Landscape BMP No. 29 – Perforated Pipe Connections BMP No. 30 – Permeable Pavement BMP No. 31 – Bioretention BMP No. 32 – RainWater Harvesting BMP No. 33 – Rock Pad BMP No. 34 – Sheet Flow BMP No. 35 – Splash Block BMP No. 36 – Vegetated Roof BMP No. 37 – Rain Garden BMP No. 38 – Soil Amendment BMP No. 39 – Retained Trees No. 40 – Filterra System No. 41 – Compost Amended Vegetated Filter Strip (CAVFS) No. 42 – Media Filter Drain (MFD) No. 43 – Compost-Amended Biofiltration Swale APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-3 NO. 1 – DETENTION PONDS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Top or Side Slopes of Dam, Berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Storage Area Sediment accumulation Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth; pond reseeded if necessary to control erosion. Liner damaged (If applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Emergency Overflow/Spillway Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. Rock missing Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil on the spillway. Spillway restored to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-8 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the structure opening or is blocking capacity of the structure by more than 10%. No Trash or debris blocking or potentially blocking entrance to structure. Trash or debris in the structure that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the structure. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Sump of structure contains no sediment. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering structure through cracks, or maintenance person judges that structure is unsound. Structure is sealed and structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering structure through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Structure has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Ladder rungs missing or unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. FROP-T Section Damaged FROP-T T section is not securely attached to structure wall and outlet pipe structure should support at least 1,000 lbs of up or down pressure. T section securely attached to wall and outlet pipe. Structure is not in upright position (allow up to 10% from plumb). Structure in correct position. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-9 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED FROP-T Section (cont.) Damaged FROP-T (cont.) Connections to outlet pipe are not watertight or show signs of deteriorated grout. Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. Any holes—other than designed holes—in the structure. Structure has no holes other than designed holes. Cleanout Gate Damaged or missing cleanout gate Cleanout gate is missing. Replace cleanout gate. Cleanout gate is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by one maintenance person. Gate moves up and down easily and is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Orifice Plate Damaged or missing orifice plate Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Obstructions to orifice plate Any trash, debris, sediment, or vegetation blocking the plate. Plate is free of all obstructions and works as designed. Overflow Pipe Obstructions to overflow pipe Any trash or debris blocking (or having the potential of blocking) the overflow pipe. Pipe is free of all obstructions and works as designed. Deformed or damaged lip of overflow pipe Lip of overflow pipe is bent or deformed. Overflow pipe does not allow overflow at an elevation lower than design Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (If applicable) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Damaged or missing grate Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-10 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Sump of catch basin contains no sediment. Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within catch basin. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch basin is unsound. Catch basin is sealed and is structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-11 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Inlet/Outlet Pipe (cont.) Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Damaged or missing grate Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-12 NO. 6 – CONVEYANCE PIPES AND DITCHES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/root growth in pipe Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Damaged pipes Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive vegetation growth Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope. Slopes are not eroding. Rock lining out of place or missing (If applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-13 NO. 7 – DEBRIS BARRIERS (E.G., TRASH RACKS) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED. Site Trash and debris Trash or debris plugging more than 20% of the area of the barrier. Barrier clear to receive capacity flow. Sediment accumulation Sediment accumulation of greater than 20% of the area of the barrier Barrier clear to receive capacity flow. Structure Cracked, broken, or loose pipe or structure Structure which bars attached to is damaged – pipe is loose or cracked or concrete structure is cracked, broken, or loose. Structure barrier attached to is sound. Bars Incorrect bar spacing Bar spacing exceeds 6 inches. Bars have at most 6 inches spacing. Damaged or missing bars Bars are bent out of shape more than 3 inches. Bars in place with no bends more than ¾ inch. Bars are missing or entire barrier missing. Bars in place according to design. Bars are loose and rust is causing 50% deterioration to any part of barrier. Repair or replace barrier to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-15 NO. 9 – FENCING MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Erosion or holes under fence Erosion or holes more than 4 inches high and 12-18 inches wide permitting access through an opening under a fence. No access under the fence. Wood Posts, Boards and Cross Members Missing or damaged parts Missing or broken boards, post out of plumb by more than 6 inches or cross members broken No gaps on fence due to missing or broken boards, post plumb to within 1½ inches, cross members sound. Weakened by rotting or insects Any part showing structural deterioration due to rotting or insect damage All parts of fence are structurally sound. Damaged or failed post foundation Concrete or metal attachments deteriorated or unable to support posts. Post foundation capable of supporting posts even in strong wind. Metal Posts, Rails and Fabric Damaged parts Post out of plumb more than 6 inches. Post plumb to within 1½ inches. Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence (including post, top rails, and fabric) more than 1 foot out of design alignment. Fence is aligned and meets design standards. Missing or loose tension wire. Tension wire in place and holding fabric. Deteriorated paint or protective coating Part or parts that have a rusting or scaling condition that has affected structural adequacy. Structurally adequate posts or parts with a uniform protective coating. Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-18 NO. 12 – ACCESS ROADS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet (i.e., trash and debris would fill up one standards size garbage can). Roadway drivable by maintenance vehicles. Debris which could damage vehicle tires or prohibit use of road. Roadway drivable by maintenance vehicles. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Blocked roadway Any obstruction which reduces clearance above road surface to less than 14 feet. Roadway overhead clear to 14 feet high. Any obstruction restricting the access to a 10- to 12 foot width for a distance of more than 12 feet or any point restricting access to less than a 10 foot width. At least 12-foot of width on access road. Road Surface Erosion, settlement, potholes, soft spots, ruts Any surface defect which hinders or prevents maintenance access. Road drivable by maintenance vehicles. Vegetation on road surface Trees or other vegetation prevent access to facility by maintenance vehicles. Maintenance vehicles can access facility. Shoulders and Ditches Erosion Erosion within 1 foot of the roadway more than 8 inches wide and 6 inches deep. Shoulder free of erosion and matching the surrounding road. Weeds and brush Weeds and brush exceed 18 inches in height or hinder maintenance access. Weeds and brush cut to 2 inches in height or cleared in such a way as to allow maintenance access. Modular Grid Pavement Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damaged or missing blocks/grids Access surface compacted because of broken on missing modular block. Access road surface restored so road infiltrates. POWER ENGINEERS, INC. APPENDIX E FACILITY DESCRIPTION AND BOND WORKSHEETS POWER ENGINEERS, INC. FIGURE 7 EXISTING POND SCHEMATIC TOP OF FLOWCONTROL RISEREL. = 434.00'5.0'TOP EL. = 437.30'27'24.0'24.0'8.5'2'1'2'1'INLET/OUTLET PIPE INV. EL. = 425.5'BOTTOMELEV. = 425.00'TOP OF SEDIMENT STORAGEELEV. = 425.5'12.0' WIDE PONDACCESS425426427428429430431432433 434 435 436 437 438 439 438 437 43843944044112%2:12:14254252:1FLOW CONTROLSTRUCTURE (TO BEMODIFIED)EXISTINGSTATION DRAINAGEOUTFLOWEMERGENCY OVERFLOWSTRUCTURENOTE: TOTAL POND STORAGE DEPTH IS 11.8FEETTALBOT SUBSTATION EXISTING POND SCHEMATIC PLANSCALE: 1" = 40'TALBOT SUBSTATION EXISTING POND SCHEMATIC SECTION (A-A)SCALE: 1" = 20'REFERENCE DRAWINGSREVISIONSREVCKDAPPDDSGNDRNDATEDSGNCKDSCALE:DRNFOR 8.5x11 DWG ONLYTHIS DRAWING WAS PREPARED BY POWERENGINEERS, INC. FOR A SPECIFIC PROJECT,TAKING INTO CONSIDERATION THE SPECIFICAND UNIQUE REQUIREMENTS OF THE PROJECT.REUSE OF THIS DRAWING OR ANY INFORMATIONCONTAINED IN THIS DRAWING FOR ANY PURPOSEIS PROHIBITED UNLESS WRITTEN PERMISSIONFROM BOTH POWER AND POWER'S CLIENT ISGRANTED.DRAWING NUMBERREVJOB NUMBER150680PUGET SOUND ENERGYTALBOT HILLCLR INSTALLATION0 FIGURES.DWG201920192019EXISTING POND SCHEMATICFIGURE 71" = 100'TJGPPGSMTA Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 • • Section I: Project Information • • •Section II: Bond Quantities Worksheets • •Section II.a EROSION CONTROL (Stabilization/Erosion Sediment Control (ESC)) •Section II.b TRANSPORTATION (Street and Site Improvements) •Section II.c DRAINAGE (Drainage and Stormwater Facilities): •Section II.d WATER - ONLY APPLICABLE IF WATER SERVICE IS PROVIDED BY CITY OF RENTON •Section II.e SANITARY SEWER - ONLY APPLICABLE IF SEWER SERVICE IS PROVIDED BY CITY OF RENTON • • • • • • Section III. Bond Worksheet • BOND QUANTITY WORKSHEET INSTRUCTIONS This worksheet is intended to be a "working" copy of the bond quantity worksheet, which will be used throughout all phases of the project, from initial submittal to project close-out approval. Submit this workbook, in its entirety, as follows: The following forms are to be completed by the engineer/developer/applicant as applicable to the project: The Bond Worksheet form will auto-calculate and auto-populate from the information provided in Section I and Section II. This section includes all pertinent information for the project Section II contains a separate spreadsheet TAB for each of the following specialties: (1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for civil construction permit submittal. Hard copies are to be included as part of the Technical Information Report (TIR). (1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for final close-out submittal. This section must be completed in its entirety Information from this section auto-populates to all other relevant areas of the workbook This section calculates the required Permit Bond for construction permit issuance as well as the required Maintenance Bond for project close-out submittals to release the permit bond on a project. All unit prices include labor, equipment, materials, overhead and profit. Complete the 'Quantity' columns for each of the appropriate section(s). Include existing Right-of-Way (ROW), Future Public Improvements and Private Improvements. The 'Quantity Remaining' column is only to be used when a project is under construction. The City allows one (1) bond reduction during the life of the project with the exception of the maintenance period reduction. Excel will auto-calculate and auto-populate the relevant fields and subtotals throughout the document. Only the 'Quantity' columns should need completing. Additional items not included in the lists can be added under the "write-in" sections. Provide a complete description, cost estimate and unit of measure for each write-in item. Note: Private improvements, with the exception of stormwater facilities, are not included in the bond amount calculation, but must be entered on the form. Stormwater facilities (public and private) are required to be included in the bond amount. Page 1 of 1 Ref 8-H Bond Quantity Worksheet INSTRUCTIONS Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 Date Prepared: Name: PE Registration No: Firm Name: Firm Address: Phone No. Email Address: Project Name: Project Owner: CED Plan # (LUA):Phone: CED Permit # (U):Address: Site Address: Street Intersection:Addt'l Project Owner: Parcel #(s):Phone: Address: Clearing and grading greater than or equal to 5,000 board feet of timber? Yes/No:NO Water Service Provided by: If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: Abbreviated Legal Description: 2400 South Puget Drive, Renton, WA 98055 P.O. Box 97034, EST 3W N/AEdmonds Ave SE 425-462-3488 2/25/2019 Prepared by: FOR APPROVALProject Phase 1 hank.lonberg@powereng.com Hank Lonberg PE Registration No. POWER Engineers, Inc. 3 Centerpointe Dr., Ste. 500, Lake Oswego, OR, 97 503-892-6703 SITE IMPROVEMENT BOND QUANTITY WORKSHEET PROJECT INFORMATION CITY OF RENTON CITY OF RENTON 1 Select the current project status/phase from the following options: For Approval - Preliminary Data Enclosed, pending approval from the City; For Construction - Estimated Data Enclosed, Plans have been approved for contruction by the City; Project Closeout - Final Costs and Quantities Enclosed for Project Close-out Submittal Engineer Stamp Required (all cost estimates must have original wet stamp and signature) Clearing and Grading Utility Providers N/A Project Location and Description Project Owner Information Talbot Hill CLR Installation Bellevue, WA 98009 2023059003 Puget Sound Energy Page 1 of 1 Ref 8-H Bond Quantity Worksheet SECTION I PROJECT INFORMATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #:UnitReference #Price Unit Quantity CostBackfill & compaction-embankment ESC-1 6.50$ CY 400 2,600.00Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 80.00$ Each Catch Basin Protection ESC-3 35.50$ Each Crushed surfacing 1 1/4" minus ESC-4 WSDOT 9-03.9(3)95.00$ CY 120 11,400.00DitchingESC-5 9.00$ CY Excavation-bulk ESC-6 2.00$ CY 400 800.00Fence, silt ESC-7 SWDM 5.4.3.1 1.50$ LF 250 375.00Fence, Temporary (NGPE)ESC-8 1.50$ LF 200 300.00Geotextile Fabric ESC-9 2.50$ SY 50 125.00Hay Bale Silt Trap ESC-10 0.50$ Each Hydroseeding ESC-11 SWDM 5.4.2.4 0.80$ SY 1100 880.00Interceptor Swale / Dike ESC-12 1.00$ LF Jute Mesh ESC-13 SWDM 5.4.2.2 3.50$ SY Level Spreader ESC-14 1.75$ LF Mulch, by hand, straw, 3" deep ESC-15 SWDM 5.4.2.1 2.50$ SY Mulch, by machine, straw, 2" deep ESC-16 SWDM 5.4.2.1 2.00$ SY Piping, temporary, CPP, 6"ESC-17 12.00$ LF Piping, temporary, CPP, 8"ESC-18 14.00$ LF Piping, temporary, CPP, 12"ESC-19 18.00$ LF Plastic covering, 6mm thick, sandbagged ESC-20 SWDM 5.4.2.3 4.00$ SY Rip Rap, machine placed; slopes ESC-21 WSDOT 9-13.1(2)45.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22 SWDM 5.4.4.1 1,800.00$ Each 1 1,800.00Rock Construction Entrance, 100'x15'x1'ESC-23 SWDM 5.4.4.1 3,200.00$ Each Sediment pond riser assembly ESC-24 SWDM 5.4.5.2 2,200.00$ Each Sediment trap, 5' high berm ESC-25 SWDM 5.4.5.1 19.00$ LF Sed. trap, 5' high, riprapped spillway berm section ESC-26 SWDM 5.4.5.1 70.00$ LF Seeding, by hand ESC-27 SWDM 5.4.2.4 1.00$ SY Sodding, 1" deep, level ground ESC-28 SWDM 5.4.2.5 8.00$ SY Sodding, 1" deep, sloped ground ESC-29 SWDM 5.4.2.5 10.00$ SY TESC Supervisor ESC-30 110.00$ HR 40 4,400.00Water truck, dust control ESC-31 SWDM 5.4.7 140.00$ HR 15 2,100.00UnitReference #Price Unit Quantity Cost EROSION/SEDIMENT SUBTOTAL:24,780.00SALES TAX @ 10%2,478.00EROSION/SEDIMENT TOTAL:27,258.00 (A) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR EROSION & SEDIMENT CONTROL Description No.(A) WRITE-IN-ITEMS Page 1 of 1 Ref 8-H Bond Quantity Worksheet SECTION II.a EROSION_CONTROL Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #: Existing Future Public PrivateRight-of-Way Improvements Improvements (D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.CostGENERAL ITEMS Backfill & Compaction- embankment GI-1 6.00$ CYBackfill & Compaction- trench GI-2 9.00$ CY Clear/Remove Brush, by hand (SY)GI-3 1.00$ SYBollards - fixed GI-4 240.74$ Each Bollards - removable GI-5 452.34$ EachClearing/Grubbing/Tree Removal GI-6 10,000.00$ AcreExcavation - bulk GI-7 2.00$ CYExcavation - Trench GI-8 5.00$ CYFencing, cedar, 6' high GI-9 20.00$ LF Fencing, chain link, 4'GI-10 38.31$ LFFencing, chain link, vinyl coated, 6' high GI-11 20.00$ LF Fencing, chain link, gate, vinyl coated, 20' GI-12 1,400.00$ EachFill & compact - common barrow GI-13 25.00$ CYFill & compact - gravel base GI-14 27.00$ CYFill & compact - screened topsoil GI-15 39.00$ CYGabion, 12" deep, stone filled mesh GI-16 65.00$ SYGabion, 18" deep, stone filled mesh GI-17 90.00$ SYGabion, 36" deep, stone filled mesh GI-18 150.00$ SY Grading, fine, by hand GI-19 2.50$ SYGrading, fine, with grader GI-20 2.00$ SY Monuments, 3' Long GI-21 250.00$ EachSensitive Areas Sign GI-22 7.00$ EachSodding, 1" deep, sloped ground GI-23 8.00$ SYSurveying, line & grade GI-24 850.00$ DaySurveying, lot location/lines GI-25 1,800.00$ AcreTopsoil Type A (imported)GI-26 28.50$ CYTraffic control crew ( 2 flaggers )GI-27 120.00$ HR Trail, 4" chipped wood GI-28 8.00$ SYTrail, 4" crushed cinder GI-29 9.00$ SY Trail, 4" top course GI-30 12.00$ SYConduit, 2"GI-31 5.00$ LFWall, retaining, concrete GI-32 55.00$ SFWall, rockery GI-33 15.00$ SF SUBTOTAL THIS PAGE: (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) Page 1 of 3 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #: Existing Future Public PrivateRight-of-Way Improvements Improvements (D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000sy RI-1 30.00$ SYAC Grinding, 4' wide machine 1000-2000sy RI-2 16.00$ SY AC Grinding, 4' wide machine > 2000sy RI-3 10.00$ SYAC Removal/Disposal RI-4 35.00$ SY Barricade, Type III ( Permanent )RI-5 56.00$ LFGuard Rail RI-6 30.00$ LFCurb & Gutter, rolled RI-7 17.00$ LFCurb & Gutter, vertical RI-8 12.50$ LFCurb and Gutter, demolition and disposal RI-9 18.00$ LF Curb, extruded asphalt RI-10 5.50$ LFCurb, extruded concrete RI-11 7.00$ LF Sawcut, asphalt, 3" depth RI-12 1.85$ LFSawcut, concrete, per 1" depth RI-13 3.00$ LFSealant, asphalt RI-14 2.00$ LFShoulder, gravel, 4" thick RI-15 15.00$ SYSidewalk, 4" thick RI-16 38.00$ SYSidewalk, 4" thick, demolition and disposal RI-17 32.00$ SYSidewalk, 5" thick RI-18 41.00$ SY Sidewalk, 5" thick, demolition and disposal RI-19 40.00$ SYSign, Handicap RI-20 85.00$ Each Striping, per stall RI-21 7.00$ EachStriping, thermoplastic, ( for crosswalk )RI-22 3.00$ SFStriping, 4" reflectorized line RI-23 0.50$ LFAdditional 2.5" Crushed Surfacing RI-24 3.60$ SYHMA 1/2" Overlay 1.5" RI-25 14.00$ SYHMA 1/2" Overlay 2"RI-26 18.00$ SYHMA Road, 2", 4" rock, First 2500 SY RI-27 28.00$ SY HMA Road, 2", 4" rock, Qty. over 2500SY RI-28 21.00$ SYHMA Road, 4", 6" rock, First 2500 SY RI-29 45.00$ SY HMA Road, 4", 6" rock, Qty. over 2500 SY RI-30 37.00$ SYHMA Road, 4", 4.5" ATB RI-31 38.00$ SYGravel Road, 4" rock, First 2500 SY RI-32 15.00$ SYGravel Road, 4" rock, Qty. over 2500 SY RI-33 10.00$ SYThickened Edge RI-34 8.60$ LF SUBTOTAL THIS PAGE: (B)(C)(D)(E) Page 2 of 3 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #: Existing Future Public PrivateRight-of-Way Improvements Improvements (D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) PARKING LOT SURFACING No.2" AC, 2" top course rock & 4" borrow PL-1 21.00$ SY2" AC, 1.5" top course & 2.5" base course PL-2 28.00$ SY 4" select borrow PL-3 5.00$ SY1.5" top course rock & 2.5" base course PL-4 14.00$ SY SUBTOTAL PARKING LOT SURFACING: (B)(C)(D)(E) LANDSCAPING & VEGETATION No.Street Trees LA-1Median Landscaping LA-2Right-of-Way Landscaping LA-3Wetland Landscaping LA-4 SUBTOTAL LANDSCAPING & VEGETATION: (B)(C)(D)(E) TRAFFIC & LIGHTING No.Signs TR-1 Street Light System ( # of Poles)TR-2Traffic Signal TR-3Traffic Signal Modification TR-4 SUBTOTAL TRAFFIC & LIGHTING: (B)(C)(D)(E) WRITE-IN-ITEMS SUBTOTAL WRITE-IN ITEMS: STREET AND SITE IMPROVEMENTS SUBTOTAL: SALES TAX @ 10% STREET AND SITE IMPROVEMENTS TOTAL: (B)(C)(D)(E) Page 3 of 3 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #:Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.CostDRAINAGE (CPE = Corrugated Polyethylene Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.) Access Road, R/D D-1 26.00$ SY 920 23,920.00* (CBs include frame and lid)Beehive D-2 90.00$ EachThrough-curb Inlet Framework D-3 400.00$ EachCB Type I D-4 1,500.00$ EachCB Type IL D-5 1,750.00$ EachCB Type II, 48" diameter D-6 2,300.00$ Each for additional depth over 4' D-7 480.00$ FTCB Type II, 54" diameter D-8 2,500.00$ Each for additional depth over 4'D-9 495.00$ FTCB Type II, 60" diameter D-10 2,800.00$ Each for additional depth over 4'D-11 600.00$ FTCB Type II, 72" diameter D-12 6,000.00$ Each for additional depth over 4'D-13 850.00$ FTCB Type II, 96" diameter D-14 14,000.00$ Each for additional depth over 4'D-15 925.00$ FTTrash Rack, 12"D-16 350.00$ EachTrash Rack, 15"D-17 410.00$ EachTrash Rack, 18"D-18 480.00$ Each Trash Rack, 21"D-19 550.00$ EachCleanout, PVC, 4"D-20 150.00$ EachCleanout, PVC, 6"D-21 170.00$ EachCleanout, PVC, 8"D-22 200.00$ EachCulvert, PVC, 4" D-23 10.00$ LFCulvert, PVC, 6" D-24 13.00$ LFCulvert, PVC, 8" D-25 15.00$ LFCulvert, PVC, 12" D-26 23.00$ LFCulvert, PVC, 15" D-27 35.00$ LFCulvert, PVC, 18" D-28 41.00$ LFCulvert, PVC, 24"D-29 56.00$ LFCulvert, PVC, 30" D-30 78.00$ LFCulvert, PVC, 36" D-31 130.00$ LF Culvert, CMP, 8"D-32 19.00$ LFCulvert, CMP, 12"D-33 29.00$ LF SUBTOTAL THIS PAGE:23,920.00 (B)(C)(D)(E) Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES Page 1 of 5 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #:Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES DRAINAGE (Continued)Culvert, CMP, 15"D-34 35.00$ LFCulvert, CMP, 18"D-35 41.00$ LFCulvert, CMP, 24"D-36 56.00$ LFCulvert, CMP, 30"D-37 78.00$ LFCulvert, CMP, 36"D-38 130.00$ LFCulvert, CMP, 48"D-39 190.00$ LFCulvert, CMP, 60"D-40 270.00$ LFCulvert, CMP, 72"D-41 350.00$ LFCulvert, Concrete, 8"D-42 42.00$ LFCulvert, Concrete, 12"D-43 48.00$ LF 30 1,440.00 Culvert, Concrete, 15"D-44 78.00$ LFCulvert, Concrete, 18"D-45 48.00$ LFCulvert, Concrete, 24"D-46 78.00$ LFCulvert, Concrete, 30"D-47 125.00$ LFCulvert, Concrete, 36"D-48 150.00$ LFCulvert, Concrete, 42"D-49 175.00$ LF Culvert, Concrete, 48"D-50 205.00$ LFCulvert, CPE Triple Wall, 6" D-51 14.00$ LFCulvert, CPE Triple Wall, 8" D-52 16.00$ LFCulvert, CPE Triple Wall, 12" D-53 24.00$ LFCulvert, CPE Triple Wall, 15" D-54 35.00$ LFCulvert, CPE Triple Wall, 18" D-55 41.00$ LFCulvert, CPE Triple Wall, 24" D-56 56.00$ LFCulvert, CPE Triple Wall, 30" D-57 78.00$ LFCulvert, CPE Triple Wall, 36" D-58 130.00$ LFCulvert, LCPE, 6"D-59 60.00$ LFCulvert, LCPE, 8"D-60 72.00$ LFCulvert, LCPE, 12"D-61 84.00$ LFCulvert, LCPE, 15"D-62 96.00$ LFCulvert, LCPE, 18"D-63 108.00$ LFCulvert, LCPE, 24"D-64 120.00$ LFCulvert, LCPE, 30"D-65 132.00$ LFCulvert, LCPE, 36"D-66 144.00$ LFCulvert, LCPE, 48"D-67 156.00$ LFCulvert, LCPE, 54"D-68 168.00$ LF SUBTOTAL THIS PAGE:1,440.00 (B)(C)(D)(E) Page 2 of 5 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #:Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES DRAINAGE (Continued)Culvert, LCPE, 60"D-69 180.00$ LFCulvert, LCPE, 72"D-70 192.00$ LFCulvert, HDPE, 6"D-71 42.00$ LFCulvert, HDPE, 8"D-72 42.00$ LFCulvert, HDPE, 12"D-73 74.00$ LFCulvert, HDPE, 15"D-74 106.00$ LFCulvert, HDPE, 18"D-75 138.00$ LFCulvert, HDPE, 24"D-76 221.00$ LFCulvert, HDPE, 30"D-77 276.00$ LFCulvert, HDPE, 36"D-78 331.00$ LFCulvert, HDPE, 48"D-79 386.00$ LFCulvert, HDPE, 54"D-80 441.00$ LFCulvert, HDPE, 60"D-81 496.00$ LF Culvert, HDPE, 72"D-82 551.00$ LFPipe, Polypropylene, 6"D-83 84.00$ LFPipe, Polypropylene, 8"D-84 89.00$ LFPipe, Polypropylene, 12"D-85 95.00$ LFPipe, Polypropylene, 15"D-86 100.00$ LFPipe, Polypropylene, 18"D-87 106.00$ LF Pipe, Polypropylene, 24"D-88 111.00$ LFPipe, Polypropylene, 30"D-89 119.00$ LFPipe, Polypropylene, 36"D-90 154.00$ LFPipe, Polypropylene, 48"D-91 226.00$ LFPipe, Polypropylene, 54"D-92 332.00$ LFPipe, Polypropylene, 60"D-93 439.00$ LF Pipe, Polypropylene, 72"D-94 545.00$ LFCulvert, DI, 6"D-95 61.00$ LFCulvert, DI, 8"D-96 84.00$ LFCulvert, DI, 12"D-97 106.00$ LFCulvert, DI, 15"D-98 129.00$ LFCulvert, DI, 18"D-99 152.00$ LFCulvert, DI, 24"D-100 175.00$ LFCulvert, DI, 30"D-101 198.00$ LFCulvert, DI, 36"D-102 220.00$ LFCulvert, DI, 48"D-103 243.00$ LFCulvert, DI, 54"D-104 266.00$ LFCulvert, DI, 60"D-105 289.00$ LFCulvert, DI, 72"D-106 311.00$ LF SUBTOTAL THIS PAGE: (B)(C)(D)(E) Page 3 of 5 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #:Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES Specialty Drainage ItemsDitching SD-1 9.50$ CY 400 3,800.00Flow Dispersal Trench (1,436 base+)SD-3 28.00$ LF French Drain (3' depth)SD-4 26.00$ LFGeotextile, laid in trench, polypropylene SD-5 3.00$ SYMid-tank Access Riser, 48" dia, 6' deep SD-6 2,000.00$ EachPond Overflow Spillway SD-7 16.00$ SYRestrictor/Oil Separator, 12"SD-8 1,150.00$ EachRestrictor/Oil Separator, 15"SD-9 1,350.00$ EachRestrictor/Oil Separator, 18"SD-10 1,700.00$ EachRiprap, placed SD-11 42.00$ CY 17 714.00Tank End Reducer (36" diameter)SD-12 1,200.00$ EachInfiltration pond testing SD-13 125.00$ HRPermeable Pavement SD-14 Permeable Concrete Sidewalk SD-15Culvert, Box __ ft x __ ft SD-16 SUBTOTAL SPECIALTY DRAINAGE ITEMS:4,514.00 (B)(C)(D)(E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)Detention Pond SF-1 Each 1Detention Tank SF-2 Each Detention Vault SF-3 Each Infiltration Pond SF-4 Each Infiltration Tank SF-5 Each Infiltration Vault SF-6 Each Infiltration Trenches SF-7 Each Basic Biofiltration Swale SF-8 Each Wet Biofiltration Swale SF-9 Each Wetpond SF-10 Each Wetvault SF-11 Each Sand Filter SF-12 Each Sand Filter Vault SF-13 Each Linear Sand Filter SF-14 Each Proprietary Facility SF-15 Each Bioretention Facility SF-16 Each SUBTOTAL STORMWATER FACILITIES: (B)(C)(D)(E) Page 4 of 5 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #:Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES WRITE-IN-ITEMS (INCLUDE ON-SITE BMPs)WI-1 WI-2 WI-3 WI-4 WI-5 WI-6WI-7WI-8WI-9WI-10WI-11WI-12WI-13WI-14WI-15 SUBTOTAL WRITE-IN ITEMS: DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:29,874.00 SALES TAX @ 10%2,987.40 DRAINAGE AND STORMWATER FACILITIES TOTAL:32,861.40 (B)(C)(D)(E) Page 5 of 5 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #: Existing Future Public Private Right-of-Way Improvements Improvements (D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Connection to Existing Watermain W-1 2,000.00$ EachDuctile Iron Watermain, CL 52, 4 Inch Diameter W-2 50.00$ LFDuctile Iron Watermain, CL 52, 6 Inch Diameter W-3 56.00$ LFDuctile Iron Watermain, CL 52, 8 Inch Diameter W-4 60.00$ LFDuctile Iron Watermain, CL 52, 10 Inch Diameter W-5 70.00$ LF Ductile Iron Watermain, CL 52, 12 Inch Diameter W-6 80.00$ LFGate Valve, 4 inch Diameter W-7 500.00$ EachGate Valve, 6 inch Diameter W-8 700.00$ Each Gate Valve, 8 Inch Diameter W-9 800.00$ EachGate Valve, 10 Inch Diameter W-10 1,000.00$ EachGate Valve, 12 Inch Diameter W-11 1,200.00$ Each Fire Hydrant Assembly W-12 4,000.00$ EachPermanent Blow-Off Assembly W-13 1,800.00$ EachAir-Vac Assembly, 2-Inch Diameter W-14 2,000.00$ EachAir-Vac Assembly, 1-Inch Diameter W-15 1,500.00$ EachCompound Meter Assembly 3-inch Diameter W-16 8,000.00$ EachCompound Meter Assembly 4-inch Diameter W-17 9,000.00$ EachCompound Meter Assembly 6-inch Diameter W-18 10,000.00$ EachPressure Reducing Valve Station 8-inch to 10-inch W-19 20,000.00$ Each WATER SUBTOTAL: SALES TAX @ 10% WATER TOTAL: (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR WATER Quantity Remaining (Bond Reduction) (B)(C) Page 1 of 1 Ref 8-H Bond Quantity Worksheet SECTION II.d WATER Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 CED Permit #: Existing Future Public PrivateRight-of-Way Improvements Improvements (D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Clean Outs SS-1 1,000.00$ EachGrease Interceptor, 500 gallon SS-2 8,000.00$ Each Grease Interceptor, 1000 gallon SS-3 10,000.00$ EachGrease Interceptor, 1500 gallon SS-4 15,000.00$ EachSide Sewer Pipe, PVC. 4 Inch Diameter SS-5 80.00$ LF Side Sewer Pipe, PVC. 6 Inch Diameter SS-6 95.00$ LFSewer Pipe, PVC, 8 inch Diameter SS-7 105.00$ LFSewer Pipe, PVC, 12 Inch Diameter SS-8 120.00$ LF Sewer Pipe, DI, 8 inch Diameter SS-9 115.00$ LFSewer Pipe, DI, 12 Inch Diameter SS-10 130.00$ LFManhole, 48 Inch Diameter SS-11 6,000.00$ EachManhole, 54 Inch Diameter SS-13 6,500.00$ EachManhole, 60 Inch Diameter SS-15 7,500.00$ EachManhole, 72 Inch Diameter SS-17 8,500.00$ EachManhole, 96 Inch Diameter SS-19 14,000.00$ EachPipe, C-900, 12 Inch Diameter SS-21 180.00$ LFOutside Drop SS-24 1,500.00$ LSInside Drop SS-25 1,000.00$ LSSewer Pipe, PVC, ____ Inch Diameter SS-26Lift Station (Entire System)SS-27 LS SANITARY SEWER SUBTOTAL: SALES TAX @ 10% SANITARY SEWER TOTAL: (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR SANITARY SEWER Quantity Remaining (Bond Reduction) (B)(C) Page 1 of 1 Ref 8-H Bond Quantity Worksheet SECTION II.e SANITARY SEWER Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 Date: Name:Project Name: PE Registration No:CED Plan # (LUA): Firm Name:CED Permit # (U): Firm Address:Site Address: Phone No.Parcel #(s): Email Address:Project Phase: Site Restoration/Erosion Sediment Control Subtotal (a) Existing Right-of-Way Improvements Subtotal (b)(b)-$ Future Public Improvements Subtotal (c)-$ Stormwater & Drainage Facilities (Public & Private) Subtotal (d)(d)32,861.40$ (e) (f) Site Restoration Civil Construction Permit Maintenance Bond 6,572.28$ Bond Reduction2 Construction Permit Bond Amount 3 Minimum Bond Amount is $10,000.00 1 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% will cover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead and profit. EST1 ((b) + (c) + (d)) x 20% -$ MAINTENANCE BOND */** (after final acceptance of construction) 27,258.00$ -$ 32,861.40$ 27,258.00$ -$ 32,861.40$ -$ 60,119.40$ P (a) x 100% SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS 2/25/2019 Hank Lonberg PE Registration No. POWER Engineers, Inc. R ((b x 150%) + (d x 100%)) S (e) x 150% + (f) x 100% Bond Reduction: Existing Right-of-Way Improvements (Quantity Remaining)2 Bond Reduction: Stormwater & Drainage Facilities (Quantity Remaining)2 T (P +R - S) Prepared by:Project Information CONSTRUCTION BOND AMOUNT */** (prior to permit issuance) 503-892-6703 hank.lonberg@powereng.com Talbot Hill CLR Installation 2400 South Puget Drive, Renton, WA 98055 2023059003 FOR APPROVAL 3 Centerpointe Dr., Ste. 500, Lake Oswego, OR, 97035 Page 1 of 1 Ref 8-H Bond Quantity Worksheet SECTION III. BOND WORKSHEET Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 3/19/2019 POWER ENGINEERS, INC. APPENDIX F GEOTECHNICAL REPORT 2101 4th Avenue, Suite 950 Seattle, Washington 98121 206.728.2674 January 29, 2019 Puget Sound Energy 35131 SE Center Street, SQE-OTC Snoqualmie, Washington 98065 Attention: Christopher Russell, PE Subject: Addendum Letter Geotechnical Engineering Services Talbot Hill Substation CLR Improvements Renton, Washington File No. 0186-953-06 INTRODUCTION AND PROJECT UNDERSTANDING This letter presents the results of GeoEngineers, Inc. (GeoEngineers) additional geotechnical engineering services for the proposed current limiting reactor (CLR) improvements at the Puget Sound Energy (PSE) Talbot Hill Substation located at 2400 Puget Drive SE in Renton, Washington. We previously provided geotechnical recommendations for this project in our revised report dated February 1, 2017 and have provided geotechnical construction observation services during Phases 1 and 2 of the substation improvements. This letter incorporates and supersedes a previous draft dated January 25, 2019. The Talbot Hill substation is located adjacent to the Bonneville Power Administration (BPA) Maple Valley substation, and the two substations are interconnected. We understand BPA has identified potential risks to their substation equipment in the event of an interconnection electrical fault. The site is shown in relation to existing improvements in the Vicinity Map, Figure 1 and the Site Plan, Figure 2. This project involves constructing six CLRs, one for each phase of the two transmission line interties, which will act as surge protectors. The CLRs will be installed on elevated pedestals in a new yard area at the southeast corner of the existing PSE Talbot Hill Substation (approximately 190 feet long and 85 feet wide). The CLR yard area will be accessed by a new gravel access road. We understand the new yard area will involve some grading but will not require retaining walls. The existing topography in the area of the proposed CLR yard is slightly uneven, ranging from Elevation 441 to 445 feet. Our geotechnical engineering services were completed in accordance with our proposal dated December 10, 2019. Our scope of work included developing geotechnical conclusions and recommendations and preparing this addendum letter. Puget Sound Energy | January 29, 2019 Page 2 File No. 0186-953-06 SITE CONDITIONS Based on explorations completed for our previous geotechnical report, the proposed CLR yard area is underlain by fill and glacial till. Boring GEI-5 was completed in the area of the proposed CLR yard area. Subsurface conditions observed in this boring (attached for reference) consist of fill overlying glacial till overlying advance outwash. The fill generally consists of medium dense silty sand placed during previous regrading at the site, extending to a depth of 7 feet. The underlying glacial till consists of medium dense to very dense silty sand with variable gravel content extending to a depth of 23 feet, where it is underlain by advance outwash consisting of very dense sand with silt. CONCLUSIONS AND RECOMMENDATIONS Critical Areas We reviewed the City of Renton online maps showing geologic critical areas including coal mine, erosion, flood, landslide and steep slope hazard areas. The site is not mapped in erosion, seismic or flood hazard areas. The site is mapped in a moderate coal mine hazard area. However, based on the depth of historical coal mining activity and the relatively shallow depth of the proposed improvements, it is our opinion there is a low coal mine hazard at the site. The site is mapped in a 25 to 40 percent steep slope area and in a moderate landslide hazard area. It is our opinion that the proposed improvements and grading will not adversely affect the stability of the slopes in or around the site. Based on our evaluation it is our opinion the soils underlying the CLR yard area have a low risk of liquefying under the design earthquake event. It is also our opinion that soils underlying the site have a low risk of lateral spread and earthquake-induced slope movement. The site is approximately 5 miles south of the Seattle Fault Zone. Based on the distance from the mapped fault, it is our opinion there is a low risk of fault rupture at the site. Geotechnical Design Recommendations We recommend the earthquake engineering, foundation design, and earthwork recommendations previously presented in our geotechnical report be used for design of the proposed CLR improvements. Stormwater Recommendations We understand the proposed stormwater improvements will be designed in accordance with the 2017 City of Renton Surface Water Design Manual. In accordance with the requirements of Chapter 5.2 of the Manual, we evaluated the site for infiltration potential. Due to the presence of shallow, medium dense to very dense glacial till, it is our opinion infiltration is not feasible on site. MaplewoodGolf Course SSeeaattttlleeSSeeaattttlleeEEaassttRentonRenton CMS P a n d P Railr o a d ST167 ST167 I-405NWA-167 SWA-167NAberdeenCt SE126thPl SESE 19thCtSE 171stPl123rdPlSES 26th Pl Loga nAveS LynnwoodAveSEJonesPlSE S 33rd PlWhitworthCt SSE 166th Pl 114thLn SEIndexCtSE S 10th StS 5th Pl 110thP lSENewportAve SES22nd Pl SE21s tCtL y n n w o o d Ct S E SE171 s tS tMain Ave SSE 5th P l S 20thPl 115thAveSES 32nd Pl S 4thPl HardieAveS WS 35t h StSmit h e r sAveSS 2 2n dCt 1 3 5 th A v e SE SE 159th St SE 166th St S 17thSt 119 t h St S E 128thPlSEShe lt onAv e SESE 29thSt 12 9t hPl SE131st A ve S ESE 173rd St S 18thSt SE18thPl UnionAve NESE4t hPl S 21stSt 133rdPlSES3r d Pl EagleLnS S E 3rdSt 117thAve SES 31s tSt Kir k landA v eSES E 2ndCt 109thAve SESE157thPlBurnet tPlS SE 16thPl SE149thSt S 3 6th St S 27th St S 9th St SE 22ndPl SE 2ndPl SE 21s tSt MonroeAveSEThom asLn SE 167t hSt NE 1stPl BurnettAveS N 2nd St HighAve SWhitw or t hAve SS E 169thSt SE 163rdSt SE 3 rd P l131stPlSEWA-167 SSE1st Pl Edmon dsWayS E127thAveSE13 0thAve SEFir DrSE 170thSt NE1stSt S RentonVillagePl 119thAveSERhodyD r CedarAveSS23r d St MontereyDr NE SE19thSt S E 8 th D rSE 162nd St S 2nd St SE7thSt HarringtonPlSES 19th St 123rdAve SEHouserWayNS 6th St MillAveSTalbotCrestDrS SE 161st St H ou serW aySSE 1 59thPlDavisAve SSpruceDr SE6thS tBlaineAveNE104thAveSELakeAveS 1 2 0 t hT e r SESE1 6t h St111thAve SEBronsonWayNRosewood DrSE Maple ValleyHwy N 1 s t S t Laurel DrFerndaleAveS E S 32ndS tS E 4th S tCedarRiverParkDr WA-515 S 7th St Jones A ve SS36t h P lCedarRidge DrSE SE151st S tSE170thPl AirportWayS S 5th St 12 1stAv eSE105th Ave SES 1 4 t h S t EdmondsAveSEUnion Ave SE113thAve SE128thAve SES Tobin St S 15th St NE 2nd St SE158thSt NE3rd S t Pier ceAve SE Morris AveS 106th Ave SESGrad y W aySE8thP l S4th St IndexAve SE SE160th St SE 5th St 120thAveSESE16 5th St SE 172nd St125th Ave SE132ndPlSEGrantAveS1 2 6thA v eSEWellsAveSS 3rd St RoyalHills DrS E P u get DrS ERainierAveSWilliamsAveSRentonAveSBeacon WayS Be nsonDrSSPuget Dr SE164th St 116thAve SESE 168th StTalbotR dS Maple ValleyHwy Be n s o nRd Sµ Vicinity Map Figure 1 PSE Talbot Substation CLR Improvements Renton, Washington BellevueBellevueSeattleSeattle ¨§¦5 ¨§¦405 ¨§¦90 UV99 UV18 UV509 UV520 UV3 UV167UV16 2,000 2,0000 Feet Data Sources: ESRI Data & Maps, Street Maps 2005 Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.3. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission. Transverse Mercator, Zone 10 N North, North American Datum 1983North arrow oriented to grid northOffice: RedmondPath: \\red\projects\0\0186953\GIS\018695300_F1_VicinityMap.mxdMap Revised: 10/3/2014 ELSite CED A R R I V E R P I P E L I N E - L O C A T I O N NO T V E R I F I E D 431 427 430 4 3 5 43 8436438 438 435 436 43042 5 432 4 3 1 43 0 43 5 440 443 444 445 443445433434435 445 451 4434424414 3 9 425 430 435 435440437435430 435 438 440 438438 435 43 0 430 435 43 7 428 44443042 5 432 432 43 0425 446 4 44 445 445 43 4 436437435433 432 433434 432431 437436435 434 435 436 437 438 4 38 433 440439441442443444443442441440 446447448449450439438437436435 450449448447446444443 447 444 446 447 4 4 8ZZNNYYXXWWVVUUEE 445441442443444 DIRT RO A D 441440443 444 445 445 446 446 447448449450 446 447 436435 434433432431430 430429 430 437 435434439440438439 438 440438 436437437436438439441440439438 438437436435434433432431430429428427426425 Proposed CLR Yard Area Existing Substation Access Gate Access Road to Puget Drive SE B e a c o n W a y S o u t h Approximate Location of City of Seattle Water Main BPA Maple Valley Substation Stormwater Pond Unverified Approximate Location of Underground Cable to BPA Maple Valley Substation GEI-4 GEI-6 GEI-3 GEI-7 GEI-5 GEI-2 GEI-1 WWWWWWWWW W WWW W W WWWWWFigure 2 PSE Talbot Substation CLR Improvements Renton, Washington Site Plan W E N S Legend P:\0\0186953\CAD\06\GeoTech\018695306_F02_Site Plan.dwg TAB:F02 Date Exported: 01/14/19 - 15:42 by hmaraNotes: 1.The locations of all features shown are approximate. 2.This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication. Data Source: Base received from PSE on 1/9/2019. Projection: WA State Plane, North Zone, NAD83, US Foot Boring by GeoEngineers (September 25, 2014) Feet 020 20 GEI-1 1A 1B 2 3SA 4 5MC 6 18 18 18 18 18 18 17 15 30 28 42 63 6 inches topsoil/root zone Brown silty fine to medium sand withoccasional gravel and trace organics (loose,moist) Brown with oxidation staining silty fine to medium sand (medium dense, moist) (fill) Gray silty fine to medium sand with occasionalgravel (medium dense, moist) (fill) Gray brown silty fine to medium sand withoccasional gravel (medium dense, moist)(glacial till) Gray brown silty fine to medium sand (mediumdense, moist) Light gray brown silty fine to medium sand withoccasional gravel (dense, moist) TS SM SM SM SM SM SM 158 14 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By CEWDrilled Notes: DML Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Mini Track Rig Geologic Drill DrillingMethod Hollow-stem Auger31.5 Rope & Cathead140 (lbs) / 30 (in) Drop DrillingEquipment 9/26/20149/26/2014 None Observed 443 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)440435430425Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-5 PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-6 Sheet 1 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%)Page A-1 7%F 8 18 18 67 51 Gray brown fine to medium sand with silt andoccasional gravel (very dense, moist)(advance outwash) SP-SM 117 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 IntervalElevation (feet)420415Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-5 (continued) PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-6 Sheet 2 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%)Page A-2 Earth Science + Technology Geotechnical Engineering Services Revised Report Talbot Substation Improvements Renton, Washington for Puget Sound Energy February 1, 2017 Geotechnical Engineering Services Revised Report Talbot Substation Improvements Renton, Washington for Puget Sound Energy February 1, 2017 Plaza 600 Building 600 Stewart Street, Suite 1700 Seattle, Washington 98101 206.728.2674 February 1, 2017 | Page i File No. 0186-953-00 Table of Contents INTRODUCTION AND SCOPE .................................................................................................................................... 1 FIELD EXPLORATION AND LABORATORY TESTING ................................................................................................ 1 Field Explorations ................................................................................................................................................. 1 Laboratory Testing ............................................................................................................................................... 2 SITE CONDITIONS ..................................................................................................................................................... 2 Geology ................................................................................................................................................................. 2 Surface Conditions............................................................................................................................................... 2 Subsurface Conditions ........................................................................................................................................ 2 CONCLUSIONS AND RECOMMENDATIONS ............................................................................................................ 3 Critical Areas ........................................................................................................................................................ 3 Earthquake Engineering ...................................................................................................................................... 3 2015 IBC Seismic Design Information ........................................................................................................ 3 Shallow and Mat Foundations ............................................................................................................................ 4 General .......................................................................................................................................................... 4 Bearing Pressure ........................................................................................................................................... 4 Embedment ................................................................................................................................................... 5 Settlement ..................................................................................................................................................... 5 Lateral Resistance ........................................................................................................................................ 5 Construction Considerations ........................................................................................................................ 5 Drilled Shafts ........................................................................................................................................................ 6 General .......................................................................................................................................................... 6 Axial Capacity ................................................................................................................................................ 6 Lateral Capacity ............................................................................................................................................ 6 Drilled Shaft Settlement ............................................................................................................................... 6 Construction Considerations ........................................................................................................................ 6 Retaining Walls .................................................................................................................................................... 7 General .......................................................................................................................................................... 7 Infiltration ............................................................................................................................................................. 7 Stormwater Pond ................................................................................................................................................. 7 Earthwork ............................................................................................................................................................. 7 Clearing .......................................................................................................................................................... 7 Subgrade Preparation ................................................................................................................................... 7 Erosion and Sedimentation Control ............................................................................................................. 7 Structural Fill ................................................................................................................................................. 8 Weather Considerations ............................................................................................................................... 9 Temporary Slopes ......................................................................................................................................... 9 LIMITATIONS .......................................................................................................................................................... 10 REFERENCES ........................................................................................................................................................ 10 February 1, 2017 | Page ii File No. 0186-953-00 LIST OF FIGURES Figure 1. Vicinity Map Figure 2. Site Plan Figure 3. Spread Footing Capacity APPENDICES Appendix A. Field Explorations and Laboratory Testing Figure A-1 – Key to Exploration Logs Figures A-2 through A-8 – Logs of Borings Figures A-9 and A-10 – Sieve Analysis Results Appendix B. Report Limitations and Guidelines for Use February 1, 2017 | Page 1 File No. 0186-953-00 INTRODUCTION AND SCOPE This report summarizes the results of GeoEngineers, Inc.’s (GeoEngineers) geotechnical engineering services for the proposed improvements to the existing Puget Sound Energy (PSE) Talbot substation. The site is located west of Beacon Way South in Renton, Washington. The site is shown in relation to the surrounding area on the Vicinity Map, Figure 1, and the Site Plan, Figure 2. We provided a draft version of this report dated November 3, 2014 and final versions dated July 15, 2015 and December 5, 2016. This revised final report provides updated seismic design recommendations for the 2015 International Building Code (IBC) per City of Renton review comments and supersedes our previous reports as described. The 2012 and 2015 IBC seismic design parameters are identical and there are no changes in our conclusions and recommendations other than the referenced IBC. We understand PSE is planning several phases of work at the existing 230-kV substation. Phase 1 involves the replacement of the existing 230 kV transformer located in the middle of the existing substation. The replacement transformer will be supported on a mat foundation. We understand Phase 1 began permitting at the end of 2014 and that the construction has been completed. In 2014, the plan for Phase 2 involved grading to expand the substation to the east, toward Beacon Way South and the Bonneville Power Administration (BPA) 230-kV Maple Valley substation located on the east side of Beacon Way South. Phase 2 also includes construction of new 230-kV dead-end towers as well as support of light equipment. The dead-end towers may be supported on either mat foundations or on drilled shafts. We understand that Phase 2 was scaled back from what was originally planned in 2014 and the substation footprint will not be expanded. We have left recommendations related to the expansion in our report for documentation purposes. We understand that stormwater infiltration is not planned at the site, based on the mapped soil conditions. However, a stormwater detention pond is planned southeast of the existing substation yard. Our geotechnical engineering services were completed in general accordance with our proposal dated August 19, 2014. Our scope of work included: ■ Completing seven borings at the site; ■ Completing laboratory testing on selected soil samples from the borings; ■ Providing geotechnical conclusions and recommendations for the proposed improvements; and ■ Preparing this report. FIELD EXPLORATION AND LABORATORY TESTING Field Explorations The subsurface conditions at the site were evaluated by completing seven borings (GEI-1 through GEI-7) to depths of 16½ to 31½ feet below existing site grades. The approximate locations of the borings are shown on the Site Plan, Figure 2. A detailed description of the field exploration program is presented in Appendix A. February 1, 2017 | Page 2 File No. 0186-953-00 Laboratory Testing Soil samples were obtained during the exploration program and taken to GeoEngineers’ laboratory for further evaluation. Selected samples were tested for the determination of percent fines, moisture content, and grain size distribution (sieve analysis). A description of the laboratory testing and the test results are presented in Appendix A or on the exploration logs, as appropriate. SITE CONDITIONS Geology We reviewed available geologic maps, including the “Geologic map of the Renton quadrangle, King County, Washington” (D.R. Mullineaux, 1965) and the “Geologic Map of King County, Washington” (D. B. Booth et al. 2007). The soils mapped in the project vicinity are predominantly glacial till (Qvt), but include localized areas of ice-contact glacial deposits (Qvi) overlying the till. Glacial till typically consists of a dense to very dense heterogeneous mixture of sand, gravel, cobbles and occasional boulders in a silt and clay matrix that were deposited beneath a glacier. A zone of weathered till typically overlies the glacial till to depths of several feet below the ground surface. The ice-contact deposits tend to be similar in character to the till, but are less dense. Advance outwash is interpreted below the glacial till, based on the subsurface explorations and the geologic maps. Advance outwash generally consists of dense to very dense sand and gravel deposited by streams and rivers issuing from advancing ice sheets and subsequently overridden by a glacier. Surface Conditions The existing substation is bounded by Beacon Way South to the east, and undeveloped properties to the north, west and south. The substation is accessed by a gravel driveway off Puget Drive SE and connects to the south side of the existing substation. The substation yard is relatively flat and is surfaced with yard rock. Transmission lines generally run east and west from the substation. These include two sets of lines that connect this substation with the BPA Maple Valley substation to the east. The topography in the area of the proposed expansion is hummocky and irregular and is about 10 feet higher than the substation and approximately 15 feet higher than Beacon Way South. Vegetation in the expansion area consists of deciduous trees near the southeast corner of the existing substation and brush and blackberries in the other undeveloped areas. There is a city of Seattle water main that runs along Beacon Way South and an underground cable that connects the PSE and BPA substations. The approximate locations of the water main and underground cable are shown on the Site Plan, Figure 2. Other utilities may be present. Subsurface Conditions We explored subsurface conditions at the substation site by drilling seven borings (GEI-1 through GEI-7) at the locations shown on the Site Plan, Figure 2. Appendix A presents details of the field exploration and laboratory testing programs, including logs of borings. February 1, 2017 | Page 3 File No. 0186-953-00 Borings GEI-1 through GEI-4 were completed inside the existing substation and encountered approximately 2 to 7 feet of fill overlying glacial till. The fill generally consisted of loose sand and silty sand with variable gravel content. The glacial till generally consisted of dense to very dense silty sand with variable gravel content and extended to depths of 7 to 23 feet. Advance outwash consisting of very dense sand was encountered below the glacial till in all four borings and extended to the depths explored (21½ to 31½ feet). Borings GEI-5 through GEI-7 were completed in the area of the proposed expansion and encountered approximately 2 to 7 feet of fill consisting of loose sand and organic-rich topsoil and duff overlying glacial till. The glacial till generally consisted of dense to very dense silty sand with variable gravel content and extended to depths of 8 to 23 feet. Advance outwash consisting over very dense sand was encountered in all three borings below the glacial till and extended to the depths explored (16½ to 31½ feet). Groundwater was not encountered during drilling, as noted on the exploration logs. These observations represent a short-term condition that may not be representative of the long-term groundwater conditions at the site. Groundwater conditions observed during drilling should be considered approximate. Groundwater level is anticipated to vary as a function of precipitation, season and other factors. CONCLUSIONS AND RECOMMENDATIONS Critical Areas We reviewed the City of Renton online maps with regard to geologic critical areas including coal mine, erosion, flood, landslide and steep slope hazard areas. The site is not mapped in erosion or flood hazard areas. The site is mapped in a moderate coal mine hazard area. However, based on the depth of historical coal mining activity and the relatively shallow depth of the proposed improvements, it is our opinion there is a low coal mine hazard at the site. The site is mapped in a 25 to 40 percent steep slope area and in a moderate landslide hazard area. It is our opinion that the proposed improvements will not adversely affect the stability of the slopes in or around the site. Based on our evaluation it is our opinion the soils underlying the substation site have a low risk of liquefying under the design earthquake event. It is also our opinion that soils underlying the site have a low risk of lateral spread and earthquake-induced slope movement. The site is approximately 5 miles south of the Seattle Fault Zone, which is thought to have a recurrence interval on the order of 1,000 years. Based on the distance from the nearest mapped fault, it is our opinion there is a low risk of fault rupture at the site. Earthquake Engineering 2015 IBC Seismic Design Information We recommend the 2015 International Building Code (IBC) parameters for Soil Profile Type, short period spectral response acceleration (SS), 1-second period spectral response acceleration (S1), and Seismic Coefficients FA and FV presented in the following table: February 1, 2017 | Page 4 File No. 0186-953-00 2015 IBC PARAMETERS 2015 IBC Parameter Recommended Value Soil Profile Type C Short Period Spectral Response Acceleration, SS (percent g) 141.3 1-Second Period Spectral Response Acceleration, S1 (percent g) 52.8 Seismic Coefficient, FA 1.00 Seismic Coefficient, FV 1.30 Peak Ground Acceleration, PGA (percent g) 58.0 Note: The above spectral response accelerations are based on data from the United States Geologic Survey (USGS) National Seismic Hazard Mapping Project. Shallow and Mat Foundations General It is our opinion the proposed structures (replacement 230 kV transformer, breakers, switches and other electrical equipment) may be supported on conventional spread footings or mat foundations bearing on either dense to very dense soils where present at foundation depth, or on a minimum of 2 feet of compacted structural fill in areas of loose to medium dense soils present at foundation depth. Due to space limitations, we understand drilled shafts are preferred for support of the dead-end towers. Our recommendations for drilled shaft foundations are discussed in the “Drilled Shafts” section. Bearing Pressure Allowable Stress Design (ASD). Spread footings may be designed using an allowable soil bearing pressure of 3,000 pounds per square foot (psf). Mat foundations may be designed for an allowable bearing pressure of 1,500 psf. The allowable soil bearing pressures apply to the total of dead and long-term live loads and may be increased by up to one-third for transient loads such as wind or seismic forces. A subgrade modulus of 180 pounds per cubic inch (pci) may be used for the design of mat foundations. Load and Resistance Factor Design (LRFD). A bearing capacity chart for spread footings is presented in Figure 3. We recommend the LRFD resistance factors listed in the table below be used when evaluating strength, service and extreme limit states for spread footings. The chart is based on a 5-foot wide footing with varying lengths and may conservatively be used for wider footings. The chart was developed in accordance with American Associate of State and Highway Transportation Officials (AASHTO) methods, in conjunction with Washington State Department of Transportation (WSDOT) standards, as summarized in the WSDOT Geotechnical Design Manual. LRFD SPREAD FOOTING RESISTANCE FACTORS Limit State Resistance Factor Shear Resistance to Sliding Bearing Passive Pressure Resistance to Sliding Strength 0.8 0.45 0.5 Service 1.0 1.0 1.0 Extreme 0.9 0.9 0.9 February 1, 2017 | Page 5 File No. 0186-953-00 Embedment In general, we recommend that the bottom of foundations be embedded at least 24 inches below the lowest adjacent grade for frost protection. The foundation embedment depth may be reduced to 18 inches for small, lightly loaded footings where frost action will not affect equipment performance, or an additional 6-inch-thick layer of gravel that is not susceptible to frost may be placed below the foundations to achieve an embedment of 24 inches. The gravel should meet the requirements of “yard course” surfacing material presented in the “Structural Fill” section of this report. Settlement Provided all loose soil is removed and the subgrade is prepared as recommended under the “Construction Considerations” section below, we estimate that the total settlement of shallow foundations will be on the order of ½ to 1 inch, with the higher end of that settlement range anticipated in the southwest corner of the substation that is underlain by looser soils. The settlements will occur rapidly, essentially as loads are applied. Differential settlements between comparably loaded foundations are expected to be less than ½ inch. Lateral Resistance Lateral foundation loads may be resisted by passive resistance on the sides of foundations and by friction on the base of the foundations. For foundations supported on native soils or on structural fill placed and compacted in accordance with our recommendations, the allowable frictional resistance may be computed using a coefficient of friction of 0.4 applied to vertical dead-load forces. The allowable passive resistance may be computed using an equivalent fluid density of 250 pounds per cubic foot (pcf) (triangular distribution) if these elements are poured directly against compacted native soils or surrounded by compacted structural fill. The structural fill should extend out from the face of the foundation element for a distance at least equal to three times the height of the element and be compacted to at least 95 percent of the maximum dry density (MDD). The above coefficient of friction and passive equivalent fluid density values incorporate a factor of safety of about 1.5. Construction Considerations Following excavation for foundations, we recommend the condition of each footing excavation be observed by a qualified geotechnical engineer to evaluate if the work is completed in accordance with our recommendations and that the subsurface conditions are as anticipated. Areas of loose or soft soils present at the foundation subgrade elevation should be overexcavated to a maximum depth of 2 feet and replaced with compacted structural fill. In such instances, the zone of structural fill should extend laterally beyond the footing edges a horizontal distance at least equal to the thickness of the fill. A geotextile separator fabric may be used at the base of the overexcavation if loose/soft soils extend below the depth of the overexcavation. February 1, 2017 | Page 6 File No. 0186-953-00 Drilled Shafts General The proposed new 230-kV dead-end towers as well as lightly-loaded equipment may be supported on drilled shafts. We recommend that the drilled shafts extend to a depth of at least 15 feet below the existing ground surface. We should review the final dead-end tower locations when available and provide modifications to these recommendations if appropriate. Axial Capacity The applied axial loads on the drilled shafts for the dead-end towers are generally very small in comparison to the applied overturning moments, resulting from the tension in the wires along with possible ice and wind loading. The axial capacity of the drilled shafts in compression will be developed primarily from friction and end bearing in the medium dense to dense soils. Provided the drilled shafts are embedded at least 15 feet below the existing ground surface and into dense soils at the tip elevation, we anticipate that the allowable axial capacity for shafts at least 3 feet in diameter will be greater than 100 kips. Lateral Capacity The design of the drilled shafts will be governed by the lateral loads on the structures. The lateral capacity of the drilled shafts will develop from the stiffness of the drilled shaft and the lateral resistance of the soil surrounding the drilled shaft. We anticipate that the shafts will be designed using the L-PILETM program. For evaluation of the lateral load behavior of the drilled shafts, the parameters in the tables below can be used as input soil parameters for the L-PILETM program. The table below may conservatively be used for all the drilled shafts. LATERAL PILE ANALYSIS INPUT PARAMETERS Soil Parameter Layer 1 (fill) Layer 2 (glacial till) Layer 3 (advance outwash) Depth (ft) 0-7 7-10 10-30 Soil Type (p-y curve model) Sand (Reese) Sand (Reese) Sand (Reese) Effective Unit Weight (lb/ft3) 125 135 135 Friction Angle (degrees) 32 38 38 p-y Modulus, k (lb/in3) 25 200 150 Drilled Shaft Settlement We estimate that post-construction settlement of drilled shaft foundations, designed and installed as recommended, will be on the order of ½ inch or less. Maximum differential settlement of similarly loaded shaft foundations should be less than about one-half the post-construction settlement. Most of this settlement will occur rapidly as loads are applied. Construction Considerations Temporary casing may be required to keep the drilled holes open while drilling through the zones of sandier soils. The contractor may attempt to drill the holes without casing but should have temporary casing available for use if sloughing and caving occurs. Although not encountered in our explorations, cobbles and February 1, 2017 | Page 7 File No. 0186-953-00 boulders may be present. The excavation contractor should be prepared for these conditions. Groundwater was not encountered in our explorations. However, as discussed above, groundwater may be present depending on the conditions at the time of construction and again the contractor should be prepared to deal with these conditions. We recommend that the drilled shaft foundation excavations be observed by GeoEngineers. Retaining Walls General We anticipate retaining walls may be used in conjunction with fill and cut slopes for grade transitions in the area of the substation expansion. Based on the available space, we anticipate concrete block walls (gravity and/or reinforced) will be the preferred wall type. This type of retaining structure is moderately settlement-sensitive, and suitable foundation support is important. We anticipate that some overexcavation of loose soils will be required to achieve suitable foundation support. We can provide recommendations for design of retaining walls once the wall geometries are better defined. Infiltration It may be possible to design stormwater facilities for infiltration, provided the base of the facilities extends to the advance outwash. This may be impractical considering the grades at the site, but we can provide infiltration recommendations if this appears feasible. Stormwater Pond We understand the stormwater pond is planned with 2H:1V (horizontal:vertical) side slopes and a depth of up to 7 feet in the middle. We recommend the side slopes be protected from erosion. Earthwork We understand that earthwork was planned as part of Phase 2 of this project but is no longer anticipated. Regardless, our recommendations for earthwork are presented below. Clearing Removal and demolition of existing site improvements and structures associated with the existing substation should include removal of foundation elements. Existing voids or new depressions created during demolition and site preparation should be cleaned of loose soil or debris and backfilled with compacted structural fill. Subgrade Preparation New foundation subgrade areas should be evaluated after site grading and foundation excavation is completed. Probing should be used to evaluate the subgrade; soft areas noted during probing should be overexcavated and replaced with compacted structural fill as described in the “Shallow and Mat Foundations” section. Erosion and Sedimentation Control Potential sources or causes of erosion and sedimentation depend upon construction methods, slope length and gradient, amount of soil exposed and/or disturbed, soil type, construction sequencing and weather. February 1, 2017 | Page 8 File No. 0186-953-00 Temporary erosion protection should be used and maintained in areas with exposed or disturbed soils to help reduce the potential for erosion and reduce transport of sediment to adjacent areas and receiving waters. Temporary erosion protection should include the construction of a silt fence around the perimeter of the work area prior to the commencement of grading activities. Permanent erosion protection should be provided by re-establishing vegetation or surfacing with rock. Until the permanent erosion protection is established and the site is stabilized, site monitoring should be performed by qualified personnel to evaluate the effectiveness of the erosion control measures and repair and/or modify them as appropriate. Provisions for modifications to the erosion control system based on monitoring observations should be included in the erosion and sedimentation control plan. Structural Fill Materials Materials used for support of structures or pavements or for utility trench backfill are classified as structural fill for the purpose of this report. Structural fill material quality varies depending upon its use as described below: 1. On-site soils may be used as structural fill to support substation equipment provided it can be appropriately moisture conditioned to achieve the required compaction. If on-site soils cannot be moisture-conditioned, imported gravel borrow for support of substation equipment should conform to PSE Base Course Aggregate Specification 1275.1310 as described in the following table: BASE COURSE GRADATION US Standard Sieve Size Percent Passing (by weight) 3 inch 100 ¾ inch 70-90 ⅜ inch 60-80 ¼ inch 50-70 U.S. No. 40 < 30 U.S. No. 200 < 5 2. Structural fill placed as “yard course crushed aggregate” surfacing material should be angular crushed rock conforming to PSE Specification 1275.1330 as described in the following table: YARD COURSE GRADATION US Standard Sieve Size Percent Passing (by weight) 1½ inches 100 1 inch 60 to 100 ¾ or ⅝ inch 0 to 35 ⅜ inch 0 to 5 February 1, 2017 | Page 9 File No. 0186-953-00 On-site Soils The on-site soils generally contain a significant amount of fines and are moisture sensitive. These soils generally meet the criteria for common borrow and are suitable for use as structural fill only if construction takes place during the drier summer months. Additional considerations for wet weather construction are presented below in the “Weather Considerations” section. Fill Placement and Compaction Criteria Structural fill should be mechanically compacted to a firm, non-yielding condition. In general, structural fill should be placed in loose lifts not exceeding 8 to 10 inches in thickness. Each lift should be conditioned to the proper moisture content and compacted to the specified density before placing subsequent lifts. Structural fill should be compacted to the following criteria: ■ Structural fill placed below foundations or to establish yard subgrade should be compacted to at least 95 percent of the MDD estimated in accordance with ASTM D 1557. We recommend that a representative from our firm be present during probing of the exposed subgrade soils in structure areas prior to the placement of structural fill and during the placement of structural fill. Our representative would evaluate the adequacy of the subgrade soils and identify areas needing further work, perform in-place moisture-density tests in the fill to evaluate if the work is being done in accordance with the compaction specifications, and advise on any modifications to procedures that may be appropriate for the prevailing conditions. Weather Considerations The on-site soils contain a sufficient percentage of fines (silt) to be moisture sensitive. If the moisture content of these soils is appreciably above the optimum moisture content, these soils become muddy and unstable. During wet weather, operation of equipment on these soils will be difficult, and it will be difficult to meet the required compaction criteria. The wet weather season generally begins in early November and continues through March in Western Washington; however, periods of wet weather may occur during any month of the year. The optimum earthwork period for these types of soils is typically July through October. If wet weather earthwork is unavoidable, we recommend that: ■ Structural fill placed during the wet season or during periods of wet weather consist of gravel borrow conforming to PSE Base Course Aggregate Specification 1275.1310. ■ The ground surface in and around the work area be sloped so that surface water is directed away from the work area. The ground surface should be graded such that areas of ponded water do not develop. Measures should be taken by the contractor to prevent surface water from collecting in excavations and trenches. Measures should be implemented to remove surface water from the work area. Temporary Slopes The soils encountered at the site are classified as Type C soil, in accordance with the provisions of Title 296 WAC (Washington Administrative Code), Part N, “Excavation, Trenching and Shoring.” We recommend that temporary slopes in excess of 4 feet in height excavated in the on-site soils be inclined no steeper than 1½H:1V. Flatter slopes may be necessary if localized sloughing occurs. For open cuts at the site we recommend that: February 1, 2017 | Page 10 File No. 0186-953-00 ■ No traffic, construction equipment, stockpiles or building supplies be allowed at the top of the cut slopes within a horizontal distance of at least 5 feet from the top of the cut. ■ Exposed soil along the slope be protected from surface erosion using waterproof tarps or plastic sheeting. ■ Construction activities be scheduled so that the length of time the temporary cut is left open is kept as short as possible. ■ Erosion control measures be implemented as appropriate such that runoff from the site is reduced to the extent practical. ■ Surface water is diverted away from the excavation. ■ The general condition of the slopes be observed periodically by a geotechnical engineer to confirm adequate stability. Since the contractor has control of the construction operations, the contractor should be made responsible for the stability of cut slopes, as well as the safety of the excavations. All shoring and temporary slopes must conform to applicable local, state and federal safety regulations. LIMITATIONS We have prepared this report for the exclusive use of Puget Sound Energy and their authorized agents for the proposed Talbot Substation Improvements in Renton, Washington. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in the field of geotechnical engineering in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood. Please refer to Appendix B, Report Limitations and Guidelines for Use, for additional information pertaining to use of this report. REFERENCES D. B. Booth, K. A. Troost, and A. P. Wisher, 2007, “Geologic Map of King County, Washington,” GeoMapNW, scale 1:100,000. D. R. Mullineaux, 1965, “Geologic map of the Renton quadrangle, King County, Washington,” U.S. Geological Survey, Open-File Report M200gq, scale 1:24,000. The National Geologic Map Database (NGMDB) portal accessed via: http://ngmdb.usgs.gov/ maps/mapview/ on October 3, 2014. U.S. Geological Survey Seismic Design Maps, accessed via: http://geohazards.usgs.gov/ designmaps/us/application.php on October 3, 2014. Washington Administrative Code Safety Standards for Construction Work information portal accessed via: http://app.leg.wa.gov/wac/default.aspx?cite=296-155 on October 3, 2014. MaplewoodGolf Course SSeeaattttlleeSSeeaattttlleeEEaassttRento nRenton CMSP and P Railroad ST167 ST167 I-405NWA-167 SWA-167NAberdeenCt SE126thPl SESE 19thCtS E 1 7 1 s tP l123rdPlSES 2 6 th P lLoga nAveS LynnwoodAveSEJonesPlSE S 33rd PlWhitworthCt SSE 166th Pl 114t hLn SEIndexCtSE S 10th StS 5th Pl 110thP lSENewportAve SES22nd Pl SE21s tCtL y n n w o o d Ct S E SE171 s tS tMain Ave SSE 5th Pl S 20thPl 115thAveSES 32nd Pl S 4 thPl HardieAveS WS 35t h StSmit h e r sAveSS 2 2n dCt 1 3 5 th A v e SE SE 159th St SE 166th St S 17thSt 119th St SE 128thPlSEShe lt onAv e SESE 29thSt 12 9t hPl SE131st A ve S ESE 173rd St S 18thSt SE18thPl UnionAve NESE4t hPl S 21stSt 133rdPlSES3r d Pl EagleLnS S E 3rdSt 117thAve SES 31s tSt Kir k landA v eSES E 2ndCt 109thAve SESE157thPlBurnet tPlS SE 16thPl SE149thSt S 3 6th St S 27th St S 9th St SE 22ndPl SE 2ndPl SE 21s tSt MonroeAveSEThom asLn SE 167t hSt NE 1stPl BurnettAveS N 2nd St HighAve SWhitw or t hAve SS E 169thSt SE 163rdSt SE 3 rd P l131stPlSEWA-167 SSE1st Pl Edmon dsWayS E127thAveSE13 0thAve SEFir DrSE 170thSt NE1stSt S RentonVillagePl 119thAveSERhodyD r CedarAveSS23r d St MontereyDr NE SE19thSt S E 8 th D rSE 162nd St S 2nd St SE7thSt HarringtonPlSES 19th St 123rdAve SEHouserWayNS 6th St MillAveSTalbotCrestDrS SE 161st St H ou serW aySSE 1 59thPlDavi sAve SSpruceDr SE6thS tBlaineAveNE104thAveSELakeAveS 1 2 0 t hT e r SESE1 6t h St111thAve SEBronsonWayNRosewood DrSE Maple ValleyHwy N 1st St Laurel DrFerndaleAveS E S 32ndS tS E 4th S tCedarRiverParkDr WA-515 S 7th St Jones Ave SS36t h P lCedarRidge DrSE SE151st S tSE170thPl AirportWayS S 5th St 12 1stAv eSE105th Ave SES 1 4 t h S t EdmondsAveSEUnion Ave SE113thAve SE128thAve SES Tobin St S 15th St NE 2nd St SE158thSt NE3rd S t Pier ceAve SE Morris AveS 106th Ave SESGrad y W aySE8thP l S4th St IndexAve SE SE160th St SE 5th St 120thAveSESE16 5th St SE 172nd St125th Ave SE132ndPlSEGrantAveS1 2 6thA v eSEWellsAveSS 3rd St RoyalHills DrS E P u get DrS ERainierAveSWilliamsAveSRentonAveSBeacon WayS Be nsonDrSSPuget Dr SE164th St 116thAve SESE 168th StTalbotR dS Maple ValleyHwy Be n s o nRd Sµ Vicinity Map Figure 1 PSE Talbot Substation ImprovementsRenton, Washington BellevueBellevueSeattleSeattle ¨§¦5 ¨§¦405 ¨§¦90 UV99 UV18 UV509 UV520 UV3 UV167UV16 2,000 2,0000 Feet Data Sources: ESRI Data & Maps, Street Maps 2005 Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.3. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission. Transverse Mercator, Zone 10 N North, North American Datum 1983North arrow oriented to grid northOffice: RedmondPath: \\red\projects\0\0186953\GIS\018695300_F1_VicinityMap.mxdMap Revised: 10/3/2014 ELSite 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 56789101112131415Bearing Capacity (ksf)Footing Width (ft) Spread Footing Capacity (chart based on 5' long footing supported on structural fill/glacially consolidated soil) Unfactored Bearing Capacity Extreme Event Capacity Resistance Factor (0.9) bearing resistance for seismic loading (Section 8.10; 2010 WSDOT GDM) Strength Limit State Service Limit State; 1-inch settlement Spread Footing Capacity Figure 30186‐953‐00 Exported 2/1/17PSE Talbot Substation Imrpovements Renton, Washington APPENDIX A Field Explorations and Laboratory Testing February 1, 2017 | Page A-1 File No. 0186-953-00 APPENDIX A FIELD EXPLORATIONS AND LABORATORY TESTING Field Explorations Subsurface conditions were explored at the site by completing seven borings (GEI-1 through GEI-7). The borings were completed by Geologic Drill Exploration, Inc. of Spokane, Washington, on September 25 and 26, 2014. The locations of the explorations were estimated in the field by measuring distances from site features through taping and pacing. The approximate exploration locations are shown on the Site Plan, Figure 2. Borings The drilling contractor hand dug to a depth of 2 feet at each boring location to be clear of the grounding grid before drilling. The borings were drilled using a tracked Bobcat-mounted hollow-stem auger drill rig. The borings were continuously observed by a geotechnical engineer from our firm who examined and classified the soils encountered, obtained representative soil samples, observed groundwater conditions and prepared a detailed log of each boring. Soils encountered in the borings were visually classified in general accordance with the classification system described in Figure A-1. A key to the exploration log symbols is also presented in Figure A-1. The logs of the borings are presented in Figures A-2 through A-8. The logs reflect our interpretation of the field conditions and the results of laboratory testing and evaluation of samples. They also indicate the depths at which the soil types or their characteristics change, although the change might actually be gradual. The borings were backfilled in accordance with Washington State Department of Ecology standards. The top 6 inches of yard rock was replaced over the completed boring to match existing yard rock. Groundwater Conditions Observations of groundwater conditions were made during drilling and are noted on the exploration logs; these observations represent a short-term condition that may not be representative of the long-term groundwater conditions at the site. Groundwater conditions observed during drilling should be considered approximate. Laboratory Testing Soil samples obtained from the field explorations were transported to our laboratory and examined to confirm or modify field classifications, as well as to evaluate index properties of the soil samples. Representative samples were selected for laboratory testing consisting of the determination of the percent fines (material passing the U.S. No. 200 sieve), moisture content and grain size distribution (sieve analysis). The tests were performed in general accordance with test methods of the ASTM International (ASTM) or other applicable procedures. Percent Passing U.S. No. 200 Sieve Selected samples were “washed” through the U.S. No. 200 mesh sieve to determine the relative percentages of coarse and fine-grained particles in the soil. The percent passing value represents the percentage by weight of the sample finer than the U.S. No. 200 sieve. These tests were conducted to verify February 1, 2017 | Page A-2 File No. 0186-953-00 field descriptions and to determine the fines content for analysis purposes. The tests were conducted in general accordance with ASTM D 1140, and the results are shown on the exploration logs at the respective sample depths. Moisture Content Testing Moisture content tests were completed using ASTM D 2216 for representative samples obtained from the explorations. The results of these tests are presented on the exploration logs at the depths where the samples were obtained. Sieve Analyses Sieve analyses were performed on selected samples in general accordance with ASTM D 422 to determine the sample grain size distribution. The wet sieve analysis method was used to determine the percentage of soil greater than the U.S. No. 200 mesh sieve. The results of the sieve analyses were plotted, were classified in general accordance with the Unified Soil Classification System (USCS), and are presented in Figures A-9 and A-10. Sheen Classification NOTE: The reader must refer to the discussion in the report text and the logs of explorations for a proper understanding of subsurface conditions. Descriptions on the logs apply only at the specific exploration locations and at the time the explorations were made; they arenot warranted to be representative of subsurface conditions at other locations or times. CC Asphalt Concrete NSSS MSHSNT Shelby tube ADDITIONAL MATERIAL SYMBOLS %FALCA CPCS DSHAMC MDOCPM PIPPPPM SATXUC VS Graphic Log Contact Distinct contact between soil strata orgeologic units Approximate location of soil strata change within a geologic soil unit Approximate location of soil stratachange within a geologic soil unit Measured groundwater level in exploration, well, or piezometer Measured free product in well orpiezometer GRAPH Topsoil/ Forest Duff/Sod Direct-Push Crushed Rock/Quarry Spalls Blowcount is recorded for driven samplers as the number of blows required to advance sampler 12 inches (ordistance noted). See exploration log for hammer weightand drop. A "P" indicates sampler pushed using the weight of thedrill rig. FIGURE A-1 2.4-inch I.D. split barrel SYMBOLS TYPICAL KEY TO EXPLORATION LOGS CR Bulk or grab Piston Standard Penetration Test (SPT) DESCRIPTIONSLETTER Distinct contact between soil strata orgeologic units TS GC PT OH CH MH OL GM GP GW DESCRIPTIONS TYPICAL LETTER (APPRECIABLE AMOUNT OF FINES) MAJOR DIVISIONS POORLY-GRADED SANDS,GRAVELLY SAND PEAT, HUMUS, SWAMP SOILSWITH HIGH ORGANICCONTENTS CLEAN SANDS GRAVELS WITH FINES CLEAN GRAVELS HIGHLY ORGANIC SOILS SILTS AND CLAYS SILTS AND CLAYS SANDANDSANDY SOILS GRAVEL AND GRAVELLY SOILS (LITTLE OR NO FINES) FINEGRAINED SOILS COARSE GRAINED SOILS SW MORE THAN 50%OF COARSEFRACTIONRETAINED ON NO.4 SIEVE CL WELL-GRADED SANDS,GRAVELLY SANDS SILTY GRAVELS, GRAVEL - SAND- SILT MIXTURES LIQUID LIMITGREATER THAN 50 SILTY SANDS, SAND - SILTMIXTURES (APPRECIABLE AMOUNTOF FINES) SOIL CLASSIFICATION CHART LIQUID LIMITLESS THAN 50 SANDS WITHFINES SP(LITTLE OR NO FINES) ML SC SM NOTE: Multiple symbols are used to indicate borderline or dual soil classifications MORE THAN 50%OF COARSEFRACTIONPASSING NO. 4SIEVE CLAYEY GRAVELS, GRAVEL -SAND - CLAY MIXTURES CLAYEY SANDS, SAND - CLAYMIXTURES INORGANIC SILTS, ROCKFLOUR, CLAYEY SILTS WITHSLIGHT PLASTICITY ORGANIC SILTS AND ORGANICSILTY CLAYS OF LOWPLASTICITY INORGANIC SILTS, MICACEOUSOR DIATOMACEOUS SILTYSOILS ORGANIC CLAYS AND SILTS OFMEDIUM TO HIGH PLASTICITY INORGANIC CLAYS OF HIGHPLASTICITY MORE THAN 50%PASSING NO. 200SIEVE MORE THAN 50%RETAINED ON NO.200 SIEVE WELL-GRADED GRAVELS,GRAVEL - SAND MIXTURES POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTYCLAYS, LEAN CLAYS GRAPH SYMBOLS AC Cement Concrete Sampler Symbol Descriptions Groundwater Contact Material Description Contact No Visible SheenSlight Sheen Moderate SheenHeavy SheenNot Tested Laboratory / Field Tests Percent finesAtterberg limits Chemical analysisLaboratory compaction testConsolidation test Direct shearHydrometer analysisMoisture content Moisture content and dry densityOrganic contentPermeability or hydraulic conductivityPlasticity indexPocket penetrometer Parts per millionSieve analysisTriaxial compression Unconfined compressionVane shear 1 2 3SA 4 5 6%F 18 16 18 18 12 18 34 46 58 57 53 49 3/4-inch angular gravel Light brown silty fine to coarse sand with gravel(loose, moist) (fill) Brown fine to medium sand with silt, organicsand occasional gravel (loose, moist) (fill) Brown silty fine to medium sand withoccasional organics (dense, moist) (glacialtill) Light gray brown fine to medium sand with silt(dense, moist) Brown silty fine to medium sand withoccasional gravel (dense, moist) Gray brown silty fine to medium sand withoccasional gravel (very dense, moist) Gray brown silty fine to medium sand withoccasional gravel (very dense, moist) Becomes dense GP SM SP-SM SM SP-SM SM SM SM Excavated to 2 feet using hand tools Rough drilling 27 15 8 10 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By CEWDrilled Notes: DML Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Mini Track Rig Geologic Drill DrillingMethod Hollow-stem Auger31.5 Rope & Cathead140 (lbs) / 30 (in) Drop DrillingEquipment 9/25/20149/25/2014 None Observed 438 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)435430425420Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-1 PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-2 Sheet 1 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 7 8%F 18 18 58 52 Brown fine to medium sand with silt (verydense, moist) (advance outwash) SP-SM 1110 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 IntervalElevation (feet)415410Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-1 (continued) PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-2 Sheet 2 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 1 2SA 3%F 4 5 17 18 18 12 18 80 76 52 90/12" 53 3/4-inch angular gravel Light brown silty fine to coarse sand with gravel(loose, moist) (fill) Brown silty fine to medium sand withoccasional gravel (very dense, moist)(glacial till) Brown silty fine to medium sand with gravel(very dense, moist) Brown silty fine to medium sand (very dense,moist) (advance outwash) Brown fine to medium sand with silt andoccasional gravel (very dense, moist) Brown fine to medium sand with silt (verydense, moist) GP SM SM SM SM SP-SM SP-SM Excavated to 2 feet using hand tools 28 18 6 11 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By CEWDrilled Notes: DML Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Mini Track Rig Geologic Drill DrillingMethod Hollow-stem Auger31.5 Rope & Cathead140 (lbs) / 30 (in) Drop DrillingEquipment 9/25/20149/25/2014 None Observed 438 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)435430425420Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-2 PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-3 Sheet 1 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 6 7%F 18 18 39 12 Becomes light brown and dense Brown fine to medium sand (medium dense,moist) SP 57 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 IntervalElevation (feet)415410Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-2 (continued) PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-3 Sheet 2 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 1MC 2SA 3%F 4 5 6 18 18 18 16 18 18 14 28 31 50 52 25 3/4-inch gravel Light brown silty fine to coarse sand with gravel(loose, moist) (fill) Gray brown with oxidation staining silty fine tomedium sand with occasional gravel(medium dense, moist) (glacial till) Brown silty fine to medium sand (mediumdense, moist) Brown silty fine to medium sand with gravel(dense, moist) Brown fine to medium sand with silt andoccasional gravel (dense to very dense,moist) (advance outwash) Becomes medium dense GP SM SM SM SM SP-SM Excavated to 2 feet using hand tools 26 16 13 12 8 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By CEWDrilled Notes: DML Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Mini Track Rig Geologic Drill DrillingMethod Hollow-stem Auger21.5 Rope & Cathead140 (lbs) / 30 (in) Drop DrillingEquipment 9/25/20149/25/2014 None Observed 438 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)435430425420Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-3 PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-4 Sheet 1 of 1Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 1 2 3 4SA 5 6 7 17 18 18 18 16 18 18 9 6 29 36 40 34 59 3/4-inch gravel Light brown silty fine to coarse sand with gravel(loose, moist) (fill) Brown silty fine to medium sand withoccasional gravel (loose, moist) (fill) Lacks gravel, becomes light brown With oxidation staining Light brown fine to medium sand with silt andoccasional gravel (medium dense, moist)(advance outwash) Brown silty fine to medium sand withoccasional gravel (dense, moist) Gray brown fine to medium sand with silt(dense, moist) Gray brown fine to medium sand with silt andoccasional gravel (medium dense, moist) Becomes very dense GP SM SM SP-SM SM SP-SM SP-SM Excavated to 2 feet using hand tools 1913 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By CEWDrilled Notes: DML Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Mini Track Rig Geologic Drill DrillingMethod Hollow-stem Auger31.5 Rope & Cathead140 (lbs) / 30 (in) Drop DrillingEquipment 9/25/20149/25/2014 None Observed 438 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)435430425420Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-4 PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-5 Sheet 1 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 8MC 9 18 17 34 59 Lacks gravel, becomes dense With occasional gravel, becomes very dense 9 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 IntervalElevation (feet)415410Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-4 (continued) PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-5 Sheet 2 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 1A 1B 2 3SA 4 5MC 6 18 18 18 18 18 18 17 15 30 28 42 63 6 inches topsoil/root zone Brown silty fine to medium sand withoccasional gravel and trace organics (loose,moist) Brown with oxidation staining silty fine to medium sand (medium dense, moist) (fill) Gray silty fine to medium sand with occasionalgravel (medium dense, moist) (fill) Gray brown silty fine to medium sand withoccasional gravel (medium dense, moist)(glacial till) Gray brown silty fine to medium sand (mediumdense, moist) Light gray brown silty fine to medium sand withoccasional gravel (dense, moist) TS SM SM SM SM SM SM 158 14 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By CEWDrilled Notes: DML Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Mini Track Rig Geologic Drill DrillingMethod Hollow-stem Auger31.5 Rope & Cathead140 (lbs) / 30 (in) Drop DrillingEquipment 9/26/20149/26/2014 None Observed 443 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 20 IntervalElevation (feet)440435430425Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-5 PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-6 Sheet 1 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 7%F 8 18 18 67 51 Gray brown fine to medium sand with silt andoccasional gravel (very dense, moist)(advance outwash) SP-SM 117 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)25 30 IntervalElevation (feet)420415Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-5 (continued) PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-6 Sheet 2 of 2Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 1 2 3MC 4 5 18 16 18 14 18 27 25 32 51 78 6 inches topsoil/root zone Brown silty fine to medium sand withoccasional gravel and trace organics (loose,moist) Brown with oxidation staining silty fine tomedium sand with occasional gravel andoccasional organics (medium dense, dry)(glacial till) Brown silty fine to medium sand withoccasional gravel (medium dense, moist) Brown fine to medium sand with silt and gravel(dense, moist) Gray brown silty fine medium sand withoccaional gravel (very dense, moist) Gray brown fine to medium sand with silt andoccasional gravel (very dense, moist)(advance outwash) TS SM SM SM SP-SM SM SP-SM 7 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By CEWDrilled Notes: DML Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Mini Track Rig Geologic Drill DrillingMethod Hollow-stem Auger16.5 Rope & Cathead140 (lbs) / 30 (in) Drop DrillingEquipment 9/26/20149/26/2014 None Observed 440 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 IntervalElevation (feet)435430425Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-6 PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-7 Sheet 1 of 1Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) 1 2%F 3 4 13 18 18 18 13 43 28 46 6 inches topsoil/root zone Brown silty fine to medium sand withoccasional gravel and trace organics (loose,moist) Light brown silty fine to medium sand withoccasional gravel (medium dense, dry) (fill) Light brown silty fine to medium sand withgravel (medium dense, dry to moist) (glacial till) Brown fine to medium sand with silt andoccasional gravel (medium dense, moist)(advance outwash) Brown fine to medium sand with silt (dense,moist) TS SM SM SM SP-SM SP-SM 155 TotalDepth (ft) HammerData SystemDatum Start End Checked By Logged By CEWDrilled Notes: DML Surface Elevation (ft) Vertical Datum Driller Groundwater Depth toWater (ft)Date Measured Elevation (ft) Easting (X)Northing (Y) Mini Track Rig Geologic Drill DrillingMethod Hollow-stem Auger16.5 Rope & Cathead140 (lbs) / 30 (in) Drop DrillingEquipment 9/26/20149/26/2014 None Observed 443 Note: See Figure A-1 for explanation of symbols. FIELD DATA Depth (feet)0 5 10 15 IntervalElevation (feet)440435430Sample NameTestingRecovered (in)Graphic LogCollected SampleBlows/footMATERIAL DESCRIPTION GroupClassificationWater LevelLog of Boring GEI-7 PSE Talbot Substation Improvements Renton, Washington 0186-953-00 Project: Project Location: Project Number:Figure A-8 Sheet 1 of 1Seattle: Date:11/2/14 Path:C:\USERS\KJANCI\DESKTOP\018695300.GPJ DBTemplate/LibTemplate:GEOENGINEERS8.GDT/GEI8_GEOTECH_STANDARDREMARKS FinesContent (%)MoistureContent (%) FIGURE A-9 SIEVE ANALYSIS RESULTSEXPLORATION NUMBERDEPTH(ft)SOIL CLASSIFICATIONGEI-1GEI-2GEI-3GEI-47½ 5510Silty fine to medium sand with gravel (SM)Silty fine to medium sand with gravel (SM)Silty fine to medium sand (SM)Silty fine to medium sand (SM)0186-953-00 SAS: SAS 10-10-2014SYMBOL3/8”3” #20 #200#40 #60 #1001.5” #10#43/4”01020304050607080901000.0010.010.11101001000PERCENT PASSING BY WEIGHT .GRAIN SIZE IN MILLIMETERSU.S. STANDARD SIEVE SIZESANDSILT OR CLAYCOBBLESGRAVELCOARSE MEDIUM FINECOARSE FINEBOULDERS FIGURE A-10 SIEVE ANALYSIS RESULTSEXPLORATION NUMBERDEPTH(ft)SOIL CLASSIFICATIONGEI-57½ Silty fine to medium sand (SM)0186-953-00 SAS: SAS 10-10-2014SYMBOL3/8”3” #20 #200#40 #60 #1001.5” #10#43/4”01020304050607080901000.0010.010.11101001000PERCENT PASSING BY WEIGHT .GRAIN SIZE IN MILLIMETERSU.S. STANDARD SIEVE SIZESANDSILT OR CLAYCOBBLESGRAVELCOARSE MEDIUM FINECOARSE FINEBOULDERS APPENDIX B Report Limitations and Guidelines for Use February 1, 2017 | Page B-1 File No. 0186-953-00 APPENDIX B REPORT LIMITATIONS AND GUIDELINES FOR USE1 This appendix provides information to help you manage your risks with respect to the use of this report. Geotechnical Services Are Performed for Specific Purposes, Persons and Projects This report has been prepared for the exclusive use of Puget Sound Energy and their authorized agents. This report may be made available to prospective contractors for their bidding or estimating purposes, but our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. This report is not intended for use by others, and the information contained herein is not applicable to other sites. GeoEngineers structures our services to meet the specific needs of our clients. For example, a geotechnical or geologic study conducted for a civil engineer or architect may not fulfill the needs of a construction contractor or even another civil engineer or architect that are involved in the same project. Because each geotechnical or geologic study is unique, each geotechnical engineering or geologic report is unique, prepared solely for the specific client and project site. Our report is prepared for the exclusive use of our Client. No other party may rely on the product of our services unless we agree in advance to such reliance in writing. This is to provide our firm with reasonable protection against open-ended liability claims by third parties with which there would otherwise be no contractual limits to their actions. Within the limitations of scope, schedule and budget, our services have been executed in accordance with our Agreement with the Client and generally accepted geotechnical practices in this area at the time this report was prepared. This report should not be applied for any purpose or project except the one originally contemplated. A Geotechnical Engineering or Geologic Report Is Based on a Unique Set of Project-Specific Factors This report has been prepared for the proposed improvements to the Talbot Substation located in Renton, Washington. GeoEngineers considered a number of unique, project-specific factors when establishing the scope of services for this project and report. Unless GeoEngineers specifically indicates otherwise, do not rely on this report if it was: ■ not prepared for you, ■ not prepared for your project, ■ not prepared for the specific site explored, or ■ completed before important project changes were made. 1 Developed based on material provided by ASFE, Professional Firms Practicing in the Geosciences; www.asfe.org. February 1, 2017 | Page B-2 File No. 0186-953-00 For example, changes that can affect the applicability of this report include those that affect: ■ the function of the proposed structure; ■ elevation, configuration, location, orientation or weight of the proposed structure; ■ composition of the design team; or ■ project ownership. If important changes are made after the date of this report, GeoEngineers should be given the opportunity to review our interpretations and recommendations and provide written modifications or confirmation, as appropriate. Subsurface Conditions Can Change This geotechnical or geologic report is based on conditions that existed at the time the study was performed. The findings and conclusions of this report may be affected by the passage of time, by manmade events such as construction on or adjacent to the site, or by natural events such as floods, earthquakes, slope instability or groundwater fluctuations. Always contact GeoEngineers before applying a report to determine if it remains applicable. Most Geotechnical and Geologic Findings Are Professional Opinions Our interpretations of subsurface conditions are based on field observations from widely spaced sampling locations at the site. Site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data and then applied our professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ, sometimes significantly, from those indicated in this report. Our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. Geotechnical Engineering Report Recommendations Are Not Final Do not over-rely on the preliminary construction recommendations included in this report. These recommendations are not final, because they were developed principally from GeoEngineers’ professional judgment and opinion. GeoEngineers’ recommendations can be finalized only by observing actual subsurface conditions revealed during construction. GeoEngineers cannot assume responsibility or liability for this report's recommendations if we do not perform construction observation. Sufficient monitoring, testing and consultation by GeoEngineers should be provided during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork activities are completed in accordance with our recommendations. Retaining GeoEngineers for construction observation for this project is the most effective method of managing the risks associated with unanticipated conditions. February 1, 2017 | Page B-3 File No. 0186-953-00 A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation Misinterpretation of this report by other design team members can result in costly problems. You could lower that risk by having GeoEngineers confer with appropriate members of the design team after submitting the report. Also retain GeoEngineers to review pertinent elements of the design team's plans and specifications. Contractors can also misinterpret a geotechnical engineering or geologic report. Reduce that risk by having GeoEngineers participate in pre-bid and preconstruction conferences, and by providing construction observation. Do Not Redraw the Exploration Logs Geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation of field logs and laboratory data. To prevent errors or omissions, the logs included in a geotechnical engineering or geologic report should never be redrawn for inclusion in architectural or other design drawings. Only photographic or electronic reproduction is acceptable, but recognize that separating logs from the report can elevate risk. Give Contractors a Complete Report and Guidance Some owners and design professionals believe they can make contractors liable for unanticipated subsurface conditions by limiting what they provide for bid preparation. To help prevent costly problems, give contractors the complete geotechnical engineering or geologic report, but preface it with a clearly written letter of transmittal. In that letter, advise contractors that the report was not prepared for purposes of bid development and that the report's accuracy is limited; encourage them to confer with GeoEngineers and/or to conduct additional study to obtain the specific types of information they need or prefer. A pre-bid conference can also be valuable. Be sure contractors have sufficient time to perform additional study. Only then might an owner be in a position to give contractors the best information available, while requiring them to at least share the financial responsibilities stemming from unanticipated conditions. Further, a contingency for unanticipated conditions should be included in your project budget and schedule. Contractors Are Responsible for Site Safety on Their Own Construction Projects Our geotechnical recommendations are not intended to direct the contractor’s procedures, methods, schedule or management of the work site. The contractor is solely responsible for job site safety and for managing construction operations to minimize risks to on-site personnel and to adjacent properties. Read These Provisions Closely Some clients, design professionals and contractors may not recognize that the geoscience practices (geotechnical engineering or geology) are far less exact than other engineering and natural science disciplines. This lack of understanding can create unrealistic expectations that could lead to disappointments, claims and disputes. GeoEngineers includes these explanatory “limitations” provisions in our reports to help reduce such risks. Please confer with GeoEngineers if you are unclear how these “Report Limitations and Guidelines for Use” apply to your project or site. Geotechnical, Geologic and Environmental Reports Should Not Be Interchanged The equipment, techniques and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study and vice versa. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions or February 1, 2017 | Page B-4 File No. 0186-953-00 recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Similarly, environmental reports are not used to address geotechnical or geologic concerns regarding a specific project. Biological Pollutants GeoEngineers’ Scope of Work specifically excludes the investigation, detection, prevention or assessment of the presence of Biological Pollutants. Accordingly, this report does not include any interpretations, recommendations, findings, or conclusions regarding the detecting, assessing, preventing or abating of Biological Pollutants and no conclusions or inferences should be drawn regarding Biological Pollutants, as they may relate to this project. The term “Biological Pollutants” includes, but is not limited to, molds, fungi, spores, bacteria, and viruses, and/or any of their byproducts. If Client desires these specialized services, they should be obtained from a consultant who offers services in this specialized field. POWER ENGINEERS, INC. APPENDIX G CSWPPP 40 60 FEET20100 1" = 20' Know what'sbelow. before you dig.Call R 6' MAX. EQUIVALENT TO ATTACH FABRIC TO POSTS. AT POSTS. USE STAPLES, WIRE RINGS, OR JOINTS IN FILTER FABRIC SHALL BE SPLICED EQUIVALENT, IF STANDARD STRENGTH FABRIC USED. FILTER FABRIC MIN. 4"x4" TRENCH BACKFILL TRENCH WITH NATIVE SOIL OR 2"x4" WOOD POSTS. STEEL FENCE POSTS, REBAR, OR EQUIVALENT POST SPACING MAY BE INCREASED TO 8' IF WIRE BACKING IS USED NOTE: FILTER FABRIC FENCES SHALL BE INSTALLED ALONG CONTOUR WHENEVER POSSIBLE CONVEYED TO A SEDIMENT TRAP OR POND. AND ACTING AS A BARRIER TO FLOW AND THEN CAUSING CHANNELIZATION OF FLOWS PARALLEL TO THE FENCE. IF THIS OCCURS, REPLACE THE FENCE AND/OR REMOVE THE TRAPPED SEDIMENT. REPLACED. 1. THE GEOTEXTILE USED MUST MEET THE STANDARDS LISTED BELOW. A COPY OF THE MANUFACTURER'S FABRIC SPECIFICATIONS MUST BE AVAILABLE ON SITE. AOS (ASTM D-4751) WATER PERMITTIVITY (ASTM D-4491) GRAB TENSILE STRENGTH (ASTM D-4632) GRAB TENSILE ELONGATION (ASTM D-4632) ULTRAVIOLET RESISTANCE (ASTM D-4355) STANDARD STRENGTH FABRIC REQUIRES WIRE BACKING TO INCREASE THE STRENGTH OF THE FENCE. WIRE BACKING OR CLOSER POST SPACING MAY BE REQUIRED FOR EXTRA STRENGTH FABRIC IF FIELD PERFORMANCE WARRANTS A STRONGER FENCE. WHERE THE FENCE IS INSTALLED, THE SLOPE SHALL BE NO STEEPER THAN 2H:1V. = = = = = 30-100 SIEVE SIZE (0.60-0.15 mm) FOR SLIT FILM 50-100 SIEVE SIZE (0.30-0.15 mm) FOR OTHER FABRICS 0.02 SEC MIN. 180 LBS MIN. FOR EXTRA STRENGTH FABRIC 100 LBS MIN. FOR STANDARD STRENGTH FABRIC 30% MAX. 70% MIN. 2. 3. -1 ƒ"-1.5" WASHED GRAVEL 2'MIN2"x2" BY 14 GA WIRE OR 1. ANY DAMAGE SHALL BE REPAIRED IMMEDIATELY 2. IF CONCENTRATED FLOWS ARE EVIDENT UPHILL OF THE FENCE, THEY MUST BE INTERCEPTED AND 3. IT IS IMPORTANT TO CHECK THE UPHILL SIDE OF THE FENCE FOR SIGNS OF THE FENCE CLOGGING 4. SEDIMENT MUST BE REMOVED WHEN IT IS 6" HIGH. 5. IF THE FILTER FABRIC HAS DETERIORATED DUE TO THE ULTRAVIOLET BREAKDOWN, IT SHALL BE 12"MINDETAIL 1 SILT FENCE DESIGN AND INSTALLATION SPECIFICATIONS AND MAINTENANCE STANDARDS 2 2 2 DESIGN AND INSTALLATION SPECIFICATIONS MAINTENANCE STANDARDS Know what'sbelow. before you dig.Call R DWG NO:SHT NO:TITLE: REFERENCE DRAWINGS D-19989 D-19988 D-19986 D-19985 D-19984 D-19982 D-19980 1 1 1 1 1 1 1 VERTICAL BUS STRUCTURE FOUNDATION PLAN CHAIN LINK FENCING SECTION AND DETAILS ACCESS ROAD PLAN, PROFILES AND SECTIONS GRADING AND FENCING PLAN, SECTIONS AND DETAILS TEMPORARY EROSION/SEDIMENT CONTROL PLAN SITE PLAN AND GENERAL NOTES 19983 A NONE CLR TALBOT HILL SUBSTATION CONTROL NOTES AND DETAILS TEMPORARY EROSION/SEDIMENT 1 1 ORIGINAL ISSUE: PERMIT SUBMITTAL TAL SITESCALE:FILE NO: SHEET: REV NODRAWING NO 12345678 12345678 A B C D E A B C D E CADD NO: CLASS: DATE (M/D/Y)SUBSTATION ENGINEERING DEPARTMENT $FILE$$DATE$$USER$$$DGN$$CODE: ENGINEER REVIEWED REVISION DESCRIPTION: CAD APPROVED WO NUMBER:111024153 WO NUMBER:111024154 OF D- March 2019 DRAFT CONSTRUTION STORMWATER POLLUTION PREVENTION PLAN Talbot Hill CLR Installation, Renton, WA PROJECT NUMBER: 15060 PROJECT CONTACT: Stuart Toraason EMAIL: stuart.toraason@powereng.com PHONE: (513)326-1504 POWER ENGINEERS, INC. This page intentionally left blank. POWER ENGINEERS, INC. PREPARED FOR: PUDGET SOUND ENERGY RENTON, WASHINGTON PREPARED BY: POWER ENGINEERS, INC. 3 CENTERPOINTE, DRIVE, SUITE 500 LAKE OSWEGO, OR 97035 POWER ENGINEERS, INC. This page intentionally left blank. POWER ENGINEERS, INC. PAGE i TABLE OF CONTENTS 1.0 SITE DESCRIPTION ..................................................................................................................... 3 2.0 SITE DESCRIPTION ..................................................................................................................... 3 2.1 EXISTING CONDITIONS .................................................................................................................. 3 2.2 PROPOSED CONSTRUCTION ACTIVITIES ........................................................................................ 4 3.0 ESC MEASURES ............................................................................................................................ 5 3.1 PROPOSED BMPS .......................................................................................................................... 5 3.2 MAINTAIN BMPS .......................................................................................................................... 6 3.3 MANAGE THE PROJECT ................................................................................................................. 7 4.0 RECOMMENDED CONSTRUCTION SEQUENCE ................................................................. 7 5.0 CONSTRUCTION SCHEDULE ................................................................................................... 8 6.0 RECORD KEEPING AND REPORTING ................................................................................... 8 TABLES: TABLE 1 SITE STATISTICS ........................................................................................................ 4 APPENDICES: APPENDIX A TESC PLANS POWER ENGINEERS, INC. PAGE ii ACRONYMS AND ABBREVIATIONS BMP Best Management Practice CFS Cubic Feet per Second CLR Current Limiting Reactor CSWPPP Construction Stormwater Pollution Prevention Plan LID Low Impact Development PGIS Pollution Generating Impervious Surface PGPS Pollution Generating Pervious Surface POC Point of Compliance TIR Technical Information Report WWHM Western Washington Hydrology Model POWER ENGINEERS, INC. PAGE 3 1.0 SITE DESCRIPTION This Stormwater Pollution Prevention Plan (SWPPP) has been prepared as part of the National Pollutant Discharge Elimination System (NPDES) stormwater permit requirements for the proposed work associated with the Talbot Hill Substation CLR Expansion project. This SWPPP will be revised as necessary to reflect the Contractor’s means and methods and all revisions will follow the best management practices (BMPs) presented in this SWPPP. The purpose of this SWPPP is to describe the proposed construction activities and all temporary and permanent erosion and sediment control (TESC) measures, pollution prevention measures, inspection/monitoring activities, and recordkeeping that will be implemented during the proposed utility work. The objectives of the SWPPP are to: 1. Implement BMPs to prevent erosion and sedimentation, and to identify, reduce, eliminate or prevent stormwater contamination and water pollution from construction activity. 2. Prevent violations of surface water quality, ground water quality, or sediment management standards. 3. Prevent adverse water quality impacts during the construction phase, including impacts on beneficial uses of the receiving water by controlling peak flow rates and volumes of stormwater runoff at the Permittee’s outfalls and downstream of the outfalls. 2.0 SITE DESCRIPTION 2.1 Existing Conditions The Talbot Substation covers approximately 7.75 acres between Beacon Way South, South Puget Drive, and Grant Ave South in Renton. The site is located near the top of a ridge and is primarily accessed from South Puget Drive, which ties into a gravel driveway leading to the site. The topography inside the substation slopes slightly away from the center to promote drainage away from electrical equipment. The existing grade outside the substation fence generally slopes away from the substation except on the eastern and northwestern sides where there is elevated terrain. In general stormwater runoff flows from north to south across the expansion area. The runoff from the CLR expansion area will flow south into the existing detention pond between the substation and access road. This route presents the least constrained flow path for stormwater to exit the project area. The pond is then drained by a flow control structure and pipe network which discharges to a natural area south of the pond. Seven borings were performed as part of a geotechnical study at the project area. Five of these borings were performed inside the substation, and these discovered several feet of fill soils overlying seven to twenty-three feet of glacial till. In the area of the existing stormwater detention pond two borings were POWER ENGINEERS, INC. PAGE 4 performed which discovered several feet of loose sand and organic topsoil overlying glacial till. Advance outwash deposits were found below the till soils in all boring samples. No groundwater was encountered at the project site (GeoEngineers, 2016). TABLE 1 SITE STATISTICS DESCRIPTION QUANTITY Total Site Area (ac): 0.56 Approximate Percent Impervious Before Construction (%): 0 Approximate Percent Impervious After Construction (%): 75 Disturbed Area During Construction (ac): 0.90 Approximate Excavation Volume (CY): 2,200 2.2 Proposed Construction Activities The scope of this SWPPP for the CLR Expansion at Talbot Hill is limited to: • Access road and CRL pad grading • Installation of the new substation perimeter fence, • Paving the access road with gravel and stabilizing the CLR pad with washed stone • Modifications to the existing flow control structure in the existing pond Below is a site detail summary summarizing the land use changes for the CLR expansion. TABLE 2 LAND COVER CHANGES PRE-DEVELOPED LAND COVER ACRES PCT. IMPERVIOUS IMPERVIOUS ACRES PERVIOUS ACRES FOREST 0.56 0% 0.00 0.56 0.56 0.00 0.56 POST-DEVELOPED LAND COVER ACRES PCT. IMPERVIOUS IMPERVIOUS ACRES PERVIOUS ACRES ROAD GRAVEL 0.19 100% 0.19 0.00 PAD GRAVEL 0.29 50% 0.15 0.14 CONCRETE 0.08 100% 0.08 0.00 0.56 0.42 0.14 POWER ENGINEERS, INC. PAGE 5 3.0 ESC MEASURES 3.1 Proposed BMPs Clearing Limits To protect adjacent properties and reduce the volume of soil exposed to construction, construction limits will be clearly marked where necessary before construction begins. Ground disturbing activity will include grading for the CLR pad and the new access road construction. Natural vegetation and topsoil at the project area shall be retained to the maximum extent feasible. High visibility fence and silt fence BMPs will be used around the perimeter of the project area to ensure disturbance is kept to a minimum outside the work area. Installation Schedules: High visibility fence and silt fence will be installed before site disturbing activities begin. Inspection and Maintenance plan: Inspect the fence once every calendar week, and within 24 hours of any stormwater or non-stormwater discharge from the project site. Repair any damage to the high visibility fence immediately. Cover Measures As the project is located west of the Cascade Mountain Crest, no soils shall remain exposed and unworked for more than seven days during the dry season (May 1 to September 30) and two days during the wet season (October 1 to April 30). Between these times, exposed soils stored aboveground shall be protected with straw, wood fiber mulch, compost, plastic sheeting, or equivalent. Regardless of time, all soils shall be stabilized at the end of the shift before a holiday or weekend, and if needed, based on weather forecasts. Any areas expected to remain unworked for greater than 30 days must be seeded or sodded (King County, 1998). During the wet season, soil stockpiles with slopes greater than or equal to 3H:1V, or with over ten feet of vertical relief must be covered if they will remain unworked for over 12 hours. During the wet season sufficient cover materials to stabilize all disturbed areas must be stockpiled on site, and the Wet Season Provisions of Section D.5.s of the King County Erosion and Sediment Control Standards must be followed (King County, 1998). Permanent stabilization will be achieved by placement of yard rock within the CLR pad, road gravel along the new access road, and seeding at all grading peripheral to the pad and road where disturbed areas will not receive gravel or rock cover. Installation Schedules: BMPs will be installed as necessary on a temporary basis during construction. Inspection and Maintenance plan: Inspect once every calendar week, and within 24 hours of any stormwater or non-stormwater discharge from the project site. Repair or replace damaged BMPs immediately. Perimeter Protection Vegetation and slope characteristics vary within the project area. The eastern edge of the project area is elevated stormwater will exit the project site primarily to the south and southwest. Silt fence will be installed down gradient of disturbed areas to ensure no contaminated stormwater exits the project area. POWER ENGINEERS, INC. PAGE 6 Concrete will be poured on site for proposed electrical equipment foundations within the new CLR pad. All concrete at the project area will be handled such that no cementitious material will enter stormwater runoff. Installation Schedules: Silt fence will be installed prior to ground disturbing activities. Concrete pouring and handling procedures will be adhered to at all times. Inspection and Maintenance plan: Inspect once every calendar week, and within 24 hours of any stormwater or non-stormwater discharge from the project site. Repair or replace damaged BMPs immediately. Traffic Area Stabilization The project area will be accessed from the existing access road located on the southern edge of the substation. This access road is a stabilized surface and does not require additional stabilization. Proposed access road paving will occur from the existing access road. Surface Water Collection Outlet protection has been installed at the outlet of the existing stormwater detention pond. Installation Schedules: Existing stormwater detention pond is already completed. Inspection and Maintenance plan: Inspect once every calendar week, and within 24 hours of any stormwater or non-stormwater discharge from the project site. If there is scour observed at the outlet, the eroded area shall be protected with more conservative measures. Dewatering Control Dewatering is not anticipated at the project site, as groundwater was not encountered during field activities performed by GeoEngineers (GeoEngineers, 2016). Dust Control Wind transport of soils is not anticipated at the project site. Exposed soils will be stabilized and will not remain exposed for long periods of time. Flow Control The project area triggers Core Requirement #3: Flow Control. The existing stormwater detention pond control structure will be modified to maintain function as flow control facility’s and restrict flow rates exiting the site to acceptable limits. 3.2 Maintain BMPs All temporary and permanent erosion and sediment control BMPs will be maintained and repaired as needed to assure continued performance of their intended function. Maintenance and repair will be conducted as noted above. Visual monitoring of the BMPs will be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the project site. If the project site becomes inactive and is temporarily stabilized, the inspection frequency will be reduced to once every month (Washington State Department of Ecology, 2012). POWER ENGINEERS, INC. PAGE 7 All temporary erosion and sediment control BMPs will be removed within 30 days after the final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment will be removed and disposed of in an approved offsite location. Disturbed soil resulting from removal of BMPs or vegetation will be permanently stabilized. 3.3 Manage the Project Sediment and erosion will be controlled locally around excavations and all TESC measures will be maintained in a functional condition at all times. The SWPPP shall be modified whenever there is a change in the design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the state. The SWPPP shall be modified if, during inspections or investigations, it is determined that the SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. The SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems identified. Revisions to the SWPPP shall be completed within seven days following the inspection. The SWPPP will be updated, maintained, and implemented in accordance with Special Conditions S3, S4, and S9 of the CSWGP. Site inspections will be conducted in accordance with Special Condition S4 of the CSWGP. 4.0 RECOMMENDED CONSTRUCTION SEQUENCE 1. Pre-construction meeting. 2. Post notice of construction activity sign with name and phone number of CESCL. 3. Flag or fence clearing limits. 4. Install catch basin protection where required. 5. Install perimeter protection (silt fence). 6. Construct surface water controls simultaneously with clearing and grading for project development. 7. Maintain erosion control measures in accordance with City of Renton Standards and Manufacturers recommendations. 8. Relocate surface water controls and erosion control measures or install new measurers so that as site conditions change the erosion and sediment control is always in accordance with the City of Renton Erosion and Sediment Control Standards. 9. Cover all areas that will be unworked for more than seven days during the dry season or two days during the wet season with straw, wood fiber mulch, compost, plastic sheeting, or equivalent. 10. Stabilize all areas that reach final grade within seven days. 11. Seed or sod any areas to remain unworked for more than 30 days. 12. Upon completion of the project, all disturbed areas must be stabilized, and best management practices removed if appropriate POWER ENGINEERS, INC. PAGE 8 5.0 CONSTRUCTION SCHEDULE Construction at the site will begin between April and May of 2019 with an expected duration of approximately twelve months. 6.0 RECORD KEEPING AND REPORTING A copy of the SWPPP shall be retained on site at all times. Records will be retained during the life of the project and for a minimum of three years following project completion. Several other documents must also be retained at the site and be easily accessible. They are as follows: • General Permit • Notice of Authorization Letter Copies of the SWPPP shall be provided to the appropriate authority within 14 days of receiving a written request and furnished to the public provided the request is in writing and per permit condition S5.G of the Construction Stormwater General Permit (Washington State Department of Ecology, 2010). POWER ENGINEERS, INC. APPENDIX A TESC PLANS POWER ENGINEERS, INC. APPENDIX H PREVIOUS TIR BY HDR Technical Information Report Talbot Substation Stormwater Support Puget Sound Energy Renton, Washington April 17, 2017 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | i Contents 1 Project Overview ................................................................................................................................. 1 1.1 Existing Conditions .................................................................................................................... 1 1.2 Proposed Conditions ................................................................................................................. 2 2 Conditions and Requirements Summary ............................................................................................ 2 3 Offsite Analysis .................................................................................................................................... 4 4 Flow Control and Water Quality Facility Analysis and Design ............................................................ 8 5 Conveyance System Analysis and Design ........................................................................................ 13 6 Special Reports and Studies ............................................................................................................. 13 7 Other Permits .................................................................................................................................... 13 8 CSWPPP Analysis and Design ......................................................................................................... 14 9 Bond Quantities, Facility Summaries, and Declaration of Covenant ................................................ 17 10 Operations and Maintenance Manual ............................................................................................... 17 11 References ........................................................................................................................................ 17 Tables Table 1: Existing Condition Acreage and Peak Flow Values ........................................................................ 8 Table 2: Proposed Condition Acreage and Peak Flow Values ..................................................................... 9 Table 3: Existing and Proposed Land Use Summary ................................................................................. 10 Table 4: Pre-developed and Proposed Controlled Flow Comparison ........................................................ 12 Table 5: Additional Project Permit Requirements ....................................................................................... 14 Figures Figure 1: TIR Worksheet Figure 2: Site Location Figure 3: Drainage Basins, Subbasins, and Site Characteristics Figure 4: Soils Figure 5: Flow Chart for Determining Type of Drainage Review Required Figure 6: Offsite Analysis Figure 7: Existing Hydrology Figure 8: Proposed Hydrology Figure 9: Flow Chart for Determining Individual Lot BMP Requirements of the SWDM Figure 10: Pond Sketch Technical Information Report Talbot Substation Stormwater Support ii | November 16, 2016 Appendices Appendix A: Firmette Appendix B: Drainage System Table Appendix C: Site Photos Appendix D: Reference 11-A Flow Control Areas Appendix E: Stormwater Model Output Appendix F: Construction Stormwater Pollution Prevention Plan Appendix G: Facility Summaries and Declaration of Covenant Appendix H: Operations and Maintenance Manual Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 1 1 Project Overview Puget Sound Energy (PSE) is proposing a series of improvements at their Talbot Substation located in Renton, Washington. A copy of the TIR Worksheet (Figure 1) is located below. Figure 2 below shows the site location and adjacent critical areas. Proposed improvements will occur on the eastern side of the substation (referred to as the project area), and will include the installation of foundations, security perimeter fence, landscape screening, paving of a small portion of the access road, installation of a new stormwater drainage and flow control system, road maintenance, and on-site oil spill control best management practices (BMPs). The extent of disturbance will be approximately 5.89 acres. Approximately 4.17 acres will consist of gravel road and surface improvements. Another 1.22 acres will be for the installation of new foundations and Spill Prevention, Control, and Countermeasures (SPCC) structures. The remaining 0.5 acres will be for installation of a stormwater detention pond. The existing site contains electrical structures, and yard rock covers the ground surface. The existing and proposed conditions as well as the site constraints are described below. 1.1 Existing Conditions 1.1.1 Topography The Talbot substation covers approximately 7.75 acres between Beacon Way South, South Puget Drive, and Grant Ave South in Renton, Washington, as shown in Figure 2. The site is located near the top of a ridge and is primarily accessed from South Puget Drive, which ties into a gravel driveway leading to the site. The topography inside the substation slopes slightly away from the center to promote drainage away from electrical equipment. The existing grade outside the substation fence generally slopes away from the substation except on the eastern and northwestern sides where there is elevated terrain. 1.1.2 Drainage In general stormwater runoff flows outwards from the middle of the substation. Existing drainage pipes on the northeast and southeast sides of the substation are tied to catch basins within the fence line whose rims are slightly raised above the yard rock, preventing them from capturing flow. The perimeter path on the northeastern side of the substation is higher than the existing grade within the fence line, preventing flow from draining off the site along this edge. An elevated field along the eastern edge of the site prevents drainage away from the substation on this side. Runoff along the northeastern, eastern, and southeastern sides of the substation therefore tends to pond within the substation and infiltrate. Along the southern edge of the substation, runoff is able to flow south across the southern perimeter path and into a depression located between the substation and access road. This route presents the path of least resistance for stormwater. The depression is drained by a culvert beneath the access road to a second depression which drains eastwards, towards Grant Avenue South. Existing drainage patterns are shown in Figure 3. Existing soil types can be found on Figure 4. KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual 1/9/2009 KING COUNTY, WASHINGTON SURFACE WATER DESIGN MANUAL REFERENCE 8-A TECHNICAL INFORMATION REPORT (TIR) WORKSHEET KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 1 Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner ________________________ Phone ______________________________ Address ____________________________ ____________________________________ Project Engineer ______________________ Company ___________________________ Phone ______________________________ Project Name _________________________ DDES Permit # ________________________ Location Township ______________ Range ________________ Section ________________ Site Address __________________________ _____________________________________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS Landuse Services Subdivison / Short Subd. / UPD Building Services M/F / Commerical / SFR Clearing and Grading Right-of-Way Use Other _______________________ DFW HPA COE 404 DOE Dam Safety FEMA Floodplain COE Wetlands Other ________ Shoreline Management Structural Rockery/Vault/_____ ESA Section 7 Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review (circle): Date (include revision dates): Date of Final: Full / Targeted / Large Site ___________________ ___________________ ___________________ Type (circle one): Date (include revision dates): Date of Final: Full / Modified / Small Site __________________ __________________ __________________ Part 6 ADJUSTMENT APPROVALS Type (circle one): Standard / Complex / Preapplication / Experimental / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Date of Approval: ______________________ Puget Sound Energy 425-456-2127 355 110th Ave NE, Chris Russell Puget Sound Energy Puget Sound Energy Talbot Stormwater Support 1601 Seagull Drive, Renton, WA 98055 23 N 5 E 20 Bellevue, WA 98004 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 2 Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ _________________________________________ _________________________________________ Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan : _________________________________ Special District Overlays: __________________________________________________________ Drainage Basin: ___________________________________ Stormwater Requirements: ________________________________________________________ Part 9 ONSITE AND ADJACENT SENSITIVE AREAS River/Stream _______________________ Lake _____________________________ Wetlands ___________________________ Closed Depression ___________________ Floodplain __________________________ Other ______________________________ ___________________________________ Steep Slope ______________________ Erosion Hazard ___________________ Landslide Hazard __________________ Coal Mine Hazard __________________ Seismic Hazard ___________________ Habitat Protection __________________ _________________________________ Part 10 SOILS Soil Type _________________ _________________ _________________ _________________ Slopes _________________ _________________ _________________ _________________ Erosion Potential _________________ _________________ _________________ _________________ High Groundwater Table (within 5 feet) Other ________________________ Sole Source Aquifer Seeps/Springs Additional Sheets Attached AmC - Arents, Alderwood material AgC - Alderwood gravelly sandy loam AgD - Alderwood gravelly sandy loam 6 to 15% 8 to 15% 15 to 30% Low (K factor of 0.10) Low (K factor of 0.10) Low (K factor of 0.10) Duwamish River Core Requirements # 1 through #8 of the City of Renton Amendment to the 2009 King County Surface Water Design Manual KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 3 Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE Core 2 – Offsite Analysis_________________ Sensitive/Critical Areas___________________ SEPA________________________________ Other_________________________________ _____________________________________ LIMITATION / SITE CONSTRAINT _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________ Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Core Requirements (all 8 apply) Discharge at Natural Location Number of Natural Discharge Locations: Offsite Analysis Level: 1 / 2 / 3 dated:__________________ Flow Control (incl. facility summary sheet) Level: 1 / 2 / 3 or Exemption Number ____________ Small Site BMPs ___________________________________ Conveyance System Spill containment located at: _________________________ Erosion and Sediment Control ESC Site Supervisor: Contact Phone: After Hours Phone: Maintenance and Operation Responsibility: Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No Water Quality (include facility summary sheet) Type: Basic / Sens. Lake / Enhanced Basicm / Bog or Exemption No. ______________________ Landscape Management Plan: Yes / No Special Requirements (as applicable) Area Specific Drainage Requirements Type: CDA / SDO / MDP / BP / LMP / Shared Fac. / None Name: ________________________ Floodplain/Floodway Delineation Type: Major / Minor / Exemption / None 100-year Base Flood Elevation (or range): ______________ Datum: Flood Protection Facilities Describe: Source Control (comm./industrial landuse) Describe landuse: Describe any structural controls: 1 Around transformers on site Surface area exemption number 1. None present N/A N/A January 18th, 2016 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 4 Oil Control High-use Site: Yes / No Treatment BMP: ________________________________ Maintenance Agreement: Yes / No with whom? ____________________________________ Other Drainage Structures Describe: Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Clearing Limits Cover Measures Perimeter Protection Traffic Area Stabilization Sediment Retention Surface Water Collection Dewatering Control Dust Control Flow Control MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION Stabilize Exposed Surfaces Remove and Restore Temporary ESC Facilities Clean and Remove All Silt and Debris, Ensure Operation of Permanent Facilities Flag Limits of SAO and open space preservation areas Other ______________________ Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description Detention Infiltration Regional Facility Shared Facility Flow Control BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ Biofiltration Wetpool Media Filtration Oil Control Spill Control Flow Control BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ Detention pond Oil spill prevention, containment, and control structures will be placed around electrical facilities which employ oil. KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/9/2009 5 Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS Drainage Easement Covenant Native Growth Protection Covenant Tract Other Cast in Place Vault Retaining Wall Rockery > 4’ High Structural on Steep Slope Other Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information provided here is accurate. Signed/Date 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Talbot Substation Thu n d e r H i l l s C r e e k Gi n g e r C r e e k SE ROYAL HILLS DR S E 1 9 T H S TROLLING HILLS AVE SESE 1 8 T H P L SE 16TH PL 116TH AVE SESE 8TH DR JONES DR SEGRANT AVE SPUGET DR SES E 8 T H P L CED A R R I D G E D R S E PATH: G:\PROJECTS\WASHINGTON\PUGET_SOUND_ENERGY_007022\TALBOT_STORMWATER_SUPPORT_269966\MAP_DOCS\DRAFT\TIR FIGURES\FIGURE_2_SITE_LOCATION.MXD - USER: TAHOFFMA - DATE: 11/16/2016 TALBOT STORMWATER SUPPORT FIGURE 2 SITE LOCATION STORMWATER TIR 0500Feet O DATA SOURCE: City of Renton, King County (2016) LEGEND Project Area Roads Streams Coalmine Hazard Area Wetlands Landslide Hazard Steep Slopes Project Location SR-520 I-90 I-405 I-405 I-5 I-5 SR-167 Longest Proposed Flowpath to Flow Control Facility: 630 feet Existing and Proposed Discharge Point 440 430 4 2 0 410 430420460450420 410 410400420410 410430 4 4 0 460450450440440 440 440 42040 0 400460 440 430 420 410 Project Area Subbasin: 5.89 Acres Localized Depression Localized Depression Localized Depression PATH: G:\PROJECTS\WASHINGTON\PUGET_SOUND_ENERGY_007022\TALBOT_STORMWATER_SUPPORT_269966\MAP_DOCS\DRAFT\TIR FIGURES\FIGURE_3_DRAINAGE.MXD - USER: TAHOFFMA - DATE: 11/16/2016 TALBOT STORMWATER SUPPORT FIGURE 3 DRAINAGE BASINS, SUBBASINS, AND SITE CHARACTERISTICS STORMWATER TIR 0250Feet O DATA SOURCE: City of Renton, King County (2016) LEGEND Project Area Contours - 10 ft Interval Existing Flow Path Proposed Flow Path Existing Drainage Infrastructure Proposed Drainage Infrastructure Proposed Detention Pond Ponded Water Observed During Field Visit ROLLINGHILLSAVE SELINCOLNCT SEBLAINE CT SE ABERDEENCT SESE 16TH PLPUGET DR SEGRANT AVE S AgDAmCAgCInCBeDPATH: G:\PROJECTS\WASHINGTON\PUGET_SOUND_ENERGY_007022\TALBOT_STORMWATER_SUPPORT_269966\MAP_DOCS\DRAFT\TIR FIGURES\FIGURE_4_SOILS.MXD - USER: TAHOFFMA - DATE: 11/16/2016TALBOT STOMWATER SUPPORTFIGURE 4SOILSSTORMWATER TIR0 190FeetO DATA SOURCE: USDA Web Soil Survey,King CountyLEGENDProject AreaSoil GroupRoads 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Technical Information Report Talbot Substation Stormwater Support 2 | November 16, 2016 1.2 Proposed Conditions Proposed conditions will include a re-graded gravel surface within the substation (approximately 3.43 acres), additional SPCC structures and equipment foundations (approximately 1.22 acres), re-grading of gravel and asphalt roads (approximately 0.74 acres), and the addition of a pond for flow control (approximately 0.5 acres). The proposed conditions will increase impervious area at the site by approximately 15%. This percentage is primarily due to the addition of the SPCC structures and equipment foundations, as well as asphalt entries to the gravel access driveways. Yard rock surfaces will only be replaced or re-graded, they will not be added. The gravel surface inside the fence line of the substation will be re-graded to smooth any slight depressions in the gravel, promote flow to catch basins, and subsequently limit ponding around electrical equipment and structures. The proposed improvements will not significantly modify the grade of the existing substation or access roads. The impervious SPCC structures and equipment foundations will be added within the substation fence. The asphalt surface will be added at the intersection of the gravel access way and South Puget Drive. Drainage improvements include a new stormwater conveyance network inside the substation which will route flows to a 75,000 cubic foot stormwater detention pond located along the southeastern edge of the substation. This pond will discharge to a depression on the southern side of the existing access road, where flow will resume the existing drainage path towards Grant Avenue South. Proposed drainage facilities can be found on Figure 3. Landscape screening will be installed along the southwest side of the substation property border and the perimeter of the pond. Landscaping will replace non-native plant cover such as blackberry shrubs and non-native grasses. 2 Conditions and Requirements Summary The project is subject to the City of Renton Amendments to the 2009 King County Surface Water Design Manual (KCSWDM), as well as the City of Renton Municipal Code. According to Section 1.1.1 of the City of Renton Amendments to the KCSWDM (COR SWDM), projects resulting in 2,000 square feet or more of new impervious surface, replaced impervious surface, or new plus impervious surface, or 7,000 square feet or more of land disturbing activity require a Drainage Review. Additionally, per Section 1.1.2 of the COR SWDM projects which result in greater than 2,000 square feet of new impervious surface and greater than 35,000 square feet of pervious surface are required to perform a Full Drainage Review. Figure 5 contains the Flow Chart for Determining Type of Drainage Review Required and shows that the project requires a Full Drainage Review. Projects undergoing a Full Drainage Review must meet the Core Requirements and Special Requirements contained in the COR SWDM. These requirements are broken down and discussed in greater detail below. Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 3 2.1 Core Requirement #1: Discharge at the Natural Location Proposed projects must discharge runoff at the natural location and comply with the discharge requirements of Core Requirement #1. The proposed stormwater detention pond which collects runoff from the conveyance system within the substation discharges to the natural discharge location, as shown on Figure 3. Per the discharge requirements of Core Requirement # 1, if the proposed 100-year flow event peak discharge is greater than 0.5 CFS a conveyance system must be provided to convey concentrated runoff to an acceptable discharge point (COR SWDM, 2009). The 100-year peak flow event for the proposed project is larger than 0.5 CFS, and will be routed through the proposed conveyance system and stormwater detention pond to the natural discharge location. The proposed stormwater detention pond will control stormwater flows generated by the substation and discharge at a rate that meets the flow control regulatory requirements. 2.2 Core Requirement #2: Offsite Analysis Core Requirement #2 is discussed in detail in Section 3 of this report. 2.3 Core Requirement #3: Flow Control Core Requirement #3 is discussed in detail in Section 4 of this report. 2.4 Core Requirement #4: Conveyance System Core Requirement #4 is discussed in detail in Section 5 of this report. 2.5 Core Requirement #5: Erosion and Sediment Control Core Requirement #5 is discussed in detail in Section 8 of this report. 2.6 Core Requirement #6: Maintenance and Operations Core Requirement #6 is discussed in detail in Section 10 of this report. 2.7 Core Requirement #7: Financial Guarantees and Liability Core Requirement # 7 is discussed in detail in Section 9 of this report. 2.8 Core Requirement #8: Water Quality The project site qualifies for the Surface Area Exemption detailed in Section 1.2.8 of the COR SWDM (City of Renton, 2009). • Less than 5,000 square feet of new PGIS that is not fully dispersed will be added and Technical Information Report Talbot Substation Stormwater Support 4 | November 16, 2016 • less than 5,000 square feet of new plus replaced PGIS that is not fully dispersed will be created as part of a redevelopment project and • less than 35,000 square feet of new PGPS that is not fully dispersed will be added. Because this project adds less than 5,000 square feet of PGIS and less than 35,000 square feet of new PGPS, water quality facilities are not required at the project site. 2.9 Special Requirement #1: Adopted Area Specific Regulations This requirement is not applicable as there are no adopted area specific regulations within the project area. 2.10 Special Requirement #2: Flood Hazard Area Delineation This requirement is not applicable as the project area is not within or adjacent to a mapped FEMA flood hazard area. The FIRMETTE (a web-based software program designed to display mapped FEMA floodplains) for the project area can be found in Appendix A. 2.11 Special Requirement #3: Flood Protection Facilities This requirement is not applicable as the proposed project does not rely on an existing flood protection facility or plan to modify or construct a new flood protection facility. 2.12 Special Requirement #4: Source Controls This requirement is not applicable as the proposed project does not require a commercial building or commercial site development permit. 2.13 Special Requirement #5: Oil Control This requirement is not applicable as the proposed project does not have high use characteristics. It should be noted that Spill Prevention, Containment, and Control (SPCC) facilities will be installed around some electrical components which employ oil. 3 Offsite Analysis A Level 1 Analysis was performed to identify any potential drainage, conveyance, or environmental issues downstream of the site that could be affected by the project and require an additional level of analysis. The Level 1 Analysis consists of a resource review and a field inspection where offsite issues are identified. The resource review provides information regarding large-scale existing issues in the project area prior to a site visit. During the field inspection, evidence of on-site and off-site drainage issues or other Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 5 environmental problems are investigated and reported. The scale of the resource review and the field inspection are defined by the downstream study area. 3.1 Task 1: Study Area The study area and extent of the downstream analysis can be found on Figure 6. The USGS StreamStats application in tandem with existing topographic and stormwater conveyance data were used to define the downstream drainage path leaving the project site. As mentioned in Section 1.1.2 above, stormwater runoff exits the project site via the southern side of the substation, passing beneath the access road and eventually flowing west towards Grant Avenue South. The study area for Task 2 is required to extend 1 mile downstream of the project discharge location per Section 1.2.2.1 of the COR SWDM. The study area is required to extend upstream if backwater or upstream effects are anticipated, however the substations location near the top of a ridge precludes any of these effects. The study area for Tasks 3 through 5 must extend to a point where the proposed project area extends less than 15% of the total tributary drainage area, but not less than one-quarter mile downstream of the project area. StreamStats was used to delineate and calculate the area of the watershed, and then determine at what distance the project area composed less than 15% of the tributary drainage area. This distance was less than the minimum distance, one quarter mile and therefore one quarter mile was used for the extent the study area used in Tasks 3 through 5. 3.2 Task 2: Resource Review The resource review was conducted according to Section 2.3.1.1 of the COR SWDM. Information required to be reviewed includes FEMA Maps, presence of sensitive areas, presence of wetlands, presence of nearby 303d listed waters, soil survey information, adopted basin plans, and offsite analysis reports for other projects. The information obtained during the review is detailed below. Adopted basin plans were not available for the project area as of September 2016. FEMA floodplain information was referenced from the online FEMA Flood Map Service Center. The project site is not located within a flood hazard area. The FIRMETTE which includes the project area is located in Appendix A. King County iMap data indicates that the project area is located inside a Coal Mine Hazard Area and adjacent to an Erosion Hazard Area. City of Renton GIS data was also analyzed, and shows that environmentally sensitive or critical areas located near the project area include erosion hazard areas and landslide areas (Figure 2). The closest high-risk erosion hazard area is approximately 1,400 ft west/southwest of the site. Moderate hazard landslide areas are present on the south, southwest, and west sides of the project site. The closest high hazard landslide area is approximately 2,000 feet west of the site. The project area will not discharge directly to any erosion or landslide hazard areas. King County iMap data indicates drainage complaints approximately three quarters of a mile west of the project area, adjacent to I-405. The registered complaints were for Technical Information Report Talbot Substation Stormwater Support 6 | November 16, 2016 garbage dumping. The stormwater discharge from the proposed project area should not have an effect. Sensitive surface waters reviewed included wetlands and impaired waters. City of Renton Wetland Inventory maps for the area do not show wetlands within one mile downstream of the site. Additionally, following a review of the Department of Ecology’s 303d list of impaired waters, no impaired waters were found within one mile downstream of the site. Seven borings were performed as part of a geotechnical study at the project area. Five of the borings were performed inside of the substation, and these discovered several feet of fill soils overlaying seven to twenty-three feet of glacial till. In the area of the proposed stormwater detention pond, two borings were performed which discovered several feet of loose sand and organic topsoil overlaying glacial till. Advance outwash deposits were found below the till soils in all boring samples. No groundwater was encountered at the project site (GeoEngineers, 2016). King County iMap does not identify any stormwater quality problems within the study area. No Basin Plans or Basin Reconnaissance Summary Reports were found for surface waters downstream of the project site, and no nearby offsite analysis reports were obtained as of September 2016 from the City of Renton Development Services Division. Existing and potential problems identified above have been tabulated in the Drainage System Table, located in Appendix B. 3.3 Task 3 through 5: Field Inspection & Results The field inspection was conducted on January 18th, 2016 at the project area and the study area within ¼ mile downstream of the site. The inspection focused on areas identified in the resource review and in previous site visits, such as steep slopes and erosion hazard areas. The purpose of the inspection was to note any erosion or sedimentation, evidence of recurrent flooding, conveyance system issues, or other drainage issues present, as well as observe existing site conditions and verify the tributary drainage basin of the project site. Site photos taken during the visit are found in Appendix C. It is important to note that the field inspection took place following 0.92 inches of rainfall in the two days prior to the visit, so wet weather conditions were observed. Land use immediately adjacent to the site is primarily undeveloped. Areas to the east and west of the substation consist of tall grasses with interspersed shrubs, and the area south of the site consists of moderate to dense trees and shrubs. Grasses surround the north side of the site, with moderate to dense tree and shrub cover north of the grassy areas. The closest developed area downstream of the site is a residential development approximately 400 feet south of the site. A park lies between the residential development and the substation, and consists of lawn grass and some taller grasses around the border. South of the park is more undeveloped grassy and forested area, with a maintained mountain bike trail in the forested area. A small stream or channel was observed crossing the trail via a culvert. The stream appeared to end in the grass area to Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 7 the southwest where it converted to overland flow or infiltrated. No erosion or scour problems were identified in this area. To the east of the project area, the grade gradually slopes upward towards a ridge between the substation and Beacon Way South (gravel road). South of the project area and to the west of the gravel access road the topography is relatively flat. A slight depression is present east of the access road which extends beyond the SE corner of the substation. The west side of the substation is bounded by an approximately 10-ft wide flat area and small ridge. West of the ridge, the grade becomes much steeper. Runoff from the substation is constrained from reaching the steep slope by the ridge feature. The ridge ends just before the southwest corner of the site, where a steep access path leads southwest towards a transmission line tower. To the north of the substation is relatively flat ground with areas of ponding. One depression is present near the NE corner of the site. Two small ponded areas are present along the north edge of the site. No outlets were observed from the ponded areas. Topography downstream of the site consists of gradual slopes across a park and moderate slopes to the west and southwest through forested and grassy areas. A gravel access road intersects an undeveloped area between the park and the substation and leads to a low area south of the road near the tower at the southwest corner of the substation. The low area was identified as an additional area that would likely capture runoff from the substation. The access road continues over a small ridge. Runoff that escaped the low area would enter a forested section crisscrossed with mountain bike paths. Many small depressions were observed along the mountain bike paths. Further downstream is a grassy area west of the park. Moderate slopes continue across the grassy area to Grant Avenue South, approximately ¼ mile downstream of the site. Despite the steep slopes and paths on the west and south sides of the site, no rills or signs of erosion or sedimentation were present during the field inspection of on-site and off-site areas. Additionally, no evidence of recurrent flooding was present in the area. Ponded areas were small, no overtopping of those areas was apparent, and water levels were fairly low within the depressions despite the recent precipitation. These observations suggest that the on-site and off-site areas do not suffer from erosion or flooding drainage problems which could warrant additional flow control for the project. Conveyance observed off-site in the downstream drainage path during the inspection included two culverts. The outlet of a 4” PVC culvert was observed in a depression on the south side of the site between the access road and substation. No water was flowing in the culvert during the time of the inspection. The second culvert (4” PVC) was observed with flow present underneath a section of the mountain bike trail southwest of the site (Figure 6). About 200 feet downstream of the culvert, the flow converted into overland flow through a grassy area. No flooding or erosion issues were observed around the culvert. Based on the observations made during the field inspection, no downstream drainage problems - such as conveyance, flooding, or erosion issues - could be identified for the project area or downstream drainage path within ¼ mile of the project area. Field observations also verified the drainage basin delineation discussed in Section 1. The lack of downstream drainage problems confirms that a Level 1 Analysis is sufficient for the study area. SECTION 1.1 DRAINAGE REVIEW City of Renton 2009 Surface Water Design Manual Amendment 1-10 FIGURE 1.1.2.A FLOW CHART FOR DETERMINING TYPE OF DRAINAGE REVIEW REQUIRED Is the project a single family residential project that results in 2,000 sf of new and/or replaced impervious surface or 7,000 sf of land disturbing activity, AND meets the following criteria? The project results in 5,000 sf of new impervious surface, and 35,000 sf of new pervious surface Yes SMALL PROJECT DRAINAGE REVIEW Section 1.1.2.1 Note: The project may also be subject to Targeted Drainage Review as determined below. No Does the new or redevelopment project result in 2,000 sf of new and/or replaced impervious surface or 35,000 sf of new pervious surface? No Does the project have the characteristics of one or more of the following categories of projects (see more detailed threshold language on p. 1-13)? 1. Projects containing or adjacent to a flood, erosion, or steep slope hazard area or documented drainage problem; projects within a landslide hazard area or landslide hazard drainage area; or projects that propose 7,000 sf (1 ac if project is in Small Project Drainage Review) of land disturbing activity. 2. Projects proposing to construct or modify a drainage pipe/ditch that is 12" or larger or receives runoff from a 12" or larger drainage pipe/ditch. Yes No Yes Reassess whether drainage review is required per Section 1.1.1 (p. 1-8). TARGETED DRAINAGE REVIEW Section 1.1.2.2 Does the project result in 50 acres of new impervious surface within a subbasin or multiple subbasins that are hydraulically connected? No FULL DRAINAGE REVIEW Section 1.1.2.3 Yes LARGE PROJECT DRAINAGE REVIEW Section 1.1.2.4 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL PATH: G:\PROJECTS\WASHINGTON\PUGET_SOUND_ENERGY_007022\TALBOT_STORMWATER_SUPPORT_269966\MAP_DOCS\DRAFT\TIR FIGURES\FIGURE_6_OFFSITE_ANALYSIS.MXD - USER: TAHOFFMA - DATE: 11/16/2016TALBOT STORMWATER SUPPORTFIGURE 6OFFSITE ANALYSISSTORMWATER TIR0530FeetOLEGENDProject AreaTask 2 Study AreaTask 3, 4, and 5 Study AreaParcelBoundaryContours - 10 ft IntervalApproximateDrainage PathWetlandHazard AreaSteep SlopeErosionLandslideDuwamish - Green River WatershedNote: Task 2 Study Area Includes the Downsteram Flow Path 1 Mile Downstream of the Project AreaTasks 3 through 5 Project Area Includes the Downstream Flow Path 1/4 Mile Downstream of the Project Area 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Technical Information Report Talbot Substation Stormwater Support 8 | November 16, 2016 4 Flow Control and Water Quality Facility Analysis and Design 4.1 Existing Site Hydrology The existing condition hydrologic analysis assumed that stormwater runoff within the project area was confined to one subbasin which drains to the depression located on the southwestern corner of the project area. Drainage characteristics of the site are discussed in greater detail in Section 1.1.2 of this report. Subbasin area and drainage characteristics can be seen on Figure 7. Existing land cover is primarily yard rock with electrical equipment foundations throughout the site. Existing hydrology was calculated based on a pre-developed forested condition as the project area is located within a designated Flow Control Area per Reference 11-A of the COR SWDM (Appendix D). Existing condition peak flow values were calculated using the KCRTS modeling software. Existing acreage input to the KCRTS model and model results can be found in Table 1, below. Table 1: Existing Condition Acreage and Peak Flow Values Pre-Developed Till Forested Condition Area 5.89 Acres Peak Flow Event Discharge (CFS)* 2- Year 0.16 5-Year 0.28 10-Year 0.29 25-Year 0.37 50-Year 0.44 100-Year 0.48 *Additional KCRTS flow output can be found in Appendix E. 4.2 Proposed Site Hydrology Changes to the existing land cover include removal of existing electrical equipment and the addition of new concrete equipment foundations, placement of new yard rock within the facility, and addition of a new stormwater detention pond (Figure 8). The yard rock is considered a partially impervious surface while all other improvements are considered impervious surfaces. Per Table 3.2.2.E in the 2009 KCSWDM, yard rock (gravel) surfaces must be multiplied by an effective impervious fraction of 0.50 to determine the impervious percentage of yard rock (gravel) surfaces. The remaining fraction is considered pervious. 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 380375370355 350 345 340 33 5 330 325 320 315310305285280385 365 360 300 295420400405 395 390 290 4 3 5430425 445440430 4254 6 5 4 60455 4504404354 1 5 4 10 435430420415415410 405400405400420 420440295 460 4 55450 450450440440440440 4404304254 15 415405 405400400 400395280 460ROLLINGHILLSAVE SELINCOLNCT SEBLAINE CT SE ABERDEENCT SESE 16TH PLPUGET DR SEGRANT AVE SProject Area Subbasin:5.89 AcresLocalizedDepressionLocalizedDepressionLocalizedDepression8" CMP Culvert8" CMP Culvert12" CMP Culvert4" Culvert4" CulvertPATH: G:\PROJECTS\WASHINGTON\PUGET_SOUND_ENERGY_007022\TALBOT_STORMWATER_SUPPORT_269966\MAP_DOCS\DRAFT\TIR FIGURES\SITE_HYDROLOGY.MXD - USER: TAHOFFMA - DATE: 11/16/2016TALBOT STORMWATER SUPPORTFIGURE 7EXISTING SITE HYDROLOGYSTORMWATER TIR0200FeetOLEGENDProject AreaSubbasin BoundaryContours - 5 ft IntervalPonded Water ObservedDuring Field VisitDrainageInfrastructureApproximateDrainage PathDrainage PathRoads 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 9 Proposed condition peak flow values were calculated using the KCRTS modeling software. Proposed acreage input to the KCRTS model and model results can be found in Table 2 below. Table 2: Proposed Condition Acreage and Peak Flow Values Proposed Condition Impervious Area 3.83 Acres Proposed Condition Till Grass Area 2.06 Acres Total Area 5.89 Acres Peak Flow Event Discharge (CFS)* 2- Year 1.11 5-Year 1.20 10-Year 1.34 25-Year 1.44 50-Year 1.98 100-Year 2.25 *Additional KCRTS flow output can be found in Appendix E. 4.3 Performance Standards The project area is located within a designated Flow Control Area per Reference 11-A of the COR SWDM (Appendix D) and is subject to the Flow Control Duration Standard for forested conditions. No drainage problems have been identified within the limits of the offsite analysis (discussed in detail in Section 3), so proposed conditions must match the flow durations for pre-developed, forested rates over the range of flows from 50% of the 2-year up to the full 50-year per Table 1.2.3.A of the COR SWDM (COR SWDM, 2009). Flow control facilities are required, as the project contains greater than 2,000 square feet of new plus replaced impervious surface. In Flow Control Duration Standard areas, these facilities must mitigate for target surfaces including: New impervious surface that is not fully dispersed, New pervious surface that is not fully dispersed, Replaced impervious surface that is not fully dispersed on a parcel redevelopment project in which the total of new plus replaced impervious surface is 5,000 square feet or more. 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 430 420 405 390380375370350 345 340 325 315 310 305 300 410 395 385 360 355 330 320 295 290 335 285440435425 4204504454404 6 5 4 60 440435280 275435430420415415 4 10 405400425400365 430 455460455 440295 450450450440440440 44044043041 5 420415 415405405400400400 400400 395460400ROLLINGHILLSAVE SELINCOLNCT SEBLAINE CT SE ABERDEENCT SESE 16TH PLPUGET DR SEGRANT AVE SProject Area Subbasin:5.89 Acres75,000 CFDetention PondLocalizedDepressionLocalizedDepression24" Culvert4" Culvert4" CulvertPATH: G:\PROJECTS\WASHINGTON\PUGET_SOUND_ENERGY_007022\TALBOT_STORMWATER_SUPPORT_269966\MAP_DOCS\DRAFT\TIR FIGURES\SITE_HYDROLOGY.MXD - USER: TAHOFFMA - DATE: 11/16/2016TALBOT STORMWATER SUPPORTFIGURE 8PROPOSED SITE HYDROLOGYSTORMWATER TIR0200FeetOLEGENDProject AreaSubbasin BoundaryContours - 5 ft IntervalDrainageInfrastructureApproximateDrainage PathDrainage PathRoadsProposedDetention Pond 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Technical Information Report Talbot Substation Stormwater Support 10 | November 16, 2016 Flow control facilities and design are discussed in detail in Section 4.4. The NPGIS and pervious areas in Table 3 reflect the division of area covered by yard rock. Table 3: Existing and Proposed Land Use Summary Flow control BMPs must be provided to either supplement the flow mitigation provided by flow control facilities or provide flow mitigation where flow control facilities are not required (SWDM, 2009). These BMPs must be selected as directed in Section 5.2 of the SWDM. The proposed project area must meet the large lot high impervious BMP requirements listed in Section 5.2.1.2 of the SWDM as the project area is larger than 22,000 square feet and the impervious surface coverage is greater than 45% of the project area. Figure 5.2.1.A Flow Chart for Determining Individual Lot BMP Requirements of the SWDM is shown in Figure 9 below. SECTION 5.2 FLOW CONTROL BMP REQUIREMENTS 1/9/2009 2009 Surface Water Design Manual 5-12 FIGURE 5.2.1.A FLOW CHART FOR DETERMING INDIVIDUAL LOT BMP REQUIREMENTS Is the project on a site/lot smaller than 22,000 square feet? Is it feasible and applicable to implement full dispersion for the roof area as per Section C.2.1? No further BMPs required. Note: Any proposed connection of roof downspouts to local drainage system must be via perforated pipe connection per Section C.2.11. Is it feasible and applicable to implement full infiltration of the roof runoff as per Section C.2.2? Apply one or more of the following to impervious area >10% of site/lot for site/lot sizes <11,000 sf and > 20% of site/lot for site/lot sizes between 11,000 and 22,000 sf (For projects located in critical aquifer recharge areas these impervious area amounts double): 1. Limited Infiltration (Section C.2.3) 2. Basic Dispersion (Section C.2.4) 3. Rain Garden (Section C.2.5) 4. Permeable Pavement (Section C.2.6) 5. Rainwater Harvesting (Section C.2.7) 6. Vegetated Roof (Section C.2.8) 7. Reduced Impervious Service Credit (Section C.2.9) 8. Native Growth Retention Credit (Section C.2.10) No Yes Yes Yes No Is the project on a site/lot 22,000 square feet or larger with impervious surface coverage of 45% or less? Is it feasible and applicable to implement full dispersion on all target impervious surface as per Section C.2.1? No further BMPs required. Note: Any proposed connection of roof downspouts to local drainage system must be via perforated pipe connection per Section C.2.11. Is it feasible and applicable to implement full infiltration of the roof runoff as per Section C.2.2 or Section 5.4? One or more of the following BMPs must be implemented for that portion of target impervious surface not addressed with full dispersion or with full infiltration of roof runoff: 1. Full Infiltration (Section C.2.2 or Section 5.4) 2. Limited Infiltration (Section C.2.3) 3. Basic Dispersion (Section C.2.4) 4. Rain Garden (Section C.2.5) 5. Permeable Pavement (Section C.2.6) 6. Rainwater Harvesting (Section C.2.7) 7. Vegetated Roof (Section C.2.8) 8. Reduced Impervious Service Credit (Section C.2.9) 9. Native Growth Retention Credit (Section C.2.10) Yes Yes Yes No Is there any remaining target impervious surface not addressed with full dispersion or with full infiltration of roof runoff? No No The project must be a site/lot 22,000 square feet or larger with impervious surface coverage of more than 45%? Is it feasible and applicable to implement full dispersion on all target impervious surface as per Section C.2.1? No further BMPs required. Note: Any proposed connection of roof downspouts to local drainage system must be via perforated pipe connection per Section C.2.11. Projects with impervious area greater than 45% and equal to or less than 65% one or more of the following must be applied to an impervious area greater than or equal to 20% of the site or 40% of the target impervious surface whichever is less OR for projects greater than 65% impervious one or more of the following must be applied to an impervious area greater than or equal to 10% of site or 20% of target impervious surface, whichever is less: 1. Full Infiltration (Section 5.4) 2. Limited Infiltration (Section C.2.3) 3. Basic Dispersion (Section C.2.4) 4. Rain Garden (Section C.2.5) 5. Permeable Pavement (Section C.2.6) 6. Rainwater Harvesting (Section C.2.7) 7. Vegetated Roof (Section C.2.8) 8. Reduced Impervious Service Credit (Section C.2.9) 9. Native Growth Retention Credit (Section C.2.10) No Yes No Yes No Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 11 The following list discusses each flow control BMP and its feasibility at the project area. • Full Infiltration o The project area lies over fill materials which are not suited for infiltration BMPs. • Limited Infiltration o The project area lies over fill materials which are not suited for infiltration BMPs. • Basic Dispersion o Existing topography on the northern and eastern edges of the project area forms high ground and prevents stormwater runoff from exiting the site. These higher areas would also restrict the vegetated flow path of a basic dispersion BMP to several feet, below the acceptable value. The eastern side of the project area is within the substation and bordered by yard rock not suitable for dispersion BMPs as there is no vegetated flow path and discharging stormwater within a substation is not recommended. • Rain Garden o There is no space available within the project area for a rain garden. The projects natural discharge location is located on the southern edge of the project area, and the proposed stormwater detention pond which has been designed to mitigate for all target surfaces within the project area lies in that location. Existing topography surrounding the northern and eastern edges of the site prevents placement of a rain garden in these locations, and a rain garden could not be placed on the western edge of the project area within the substation fence. • Permeable Pavement o No major paving activities are being proposed at the project area. • Rainwater Harvesting o The control house is the only structure with a roof that lies inside the project area. Storage of rainwater associated with a rainwater harvesting facility within the fence line of the substation is not feasible. There is also no use for harvested rainwater at the project site, no plants require irrigation and there are no facilities which may use harvested water. • Vegetated Roof o Vegetated rooftops within substation facilities are not feasible as the required maintenance would involve getting on top of or near the top of the roof surface in close proximity to high voltage power facilities. Technical Information Report Talbot Substation Stormwater Support 12 | November 16, 2016 • Reduced Impervious Surface Credit o Impervious surfaces have been restricted to the maximum extent feasible. Permeable yard rock is being used where vehicle access is not required within the substation fence. Impervious surfaces within the project area include the proposed stormwater detention pond, electrical and SPCC facilities, and the access road required for vehicles. • Native Growth Retention Credit o There are no native growth areas located within the project area. The proposed flow control facility will mitigate for all target surfaces at the project area. Proposed conveyance systems must be designed to convey the 25-year peak flow event with a minimum 6 inches of freeboard to the structure grate. Developed conditions must be assumed for onsite tributary areas, while existing conditions shall be assumed for offsite tributary areas. For events greater than the 25-year peak flow, structures may overtop. However, the 100-year peak flow event may not create or exacerbate any existing severe flooding or erosion problem per Core Requirement #2 of the COR SWDM. All overflows for peak flow events up to and including the 100-year event must discharge to their natural discharge location at the project area. Stormwater water quality treatment facilities are not required at the project area as the total area of pollution-generating surfaces is below the water quality requirement thresholds. SPCC structures will be installed around electrical components requiring oil in order to prevent stormwater contamination in the event an oil spill. These are the only water quality facilities which will be present at the project site. 4.4 Flow Control System An illustrative sketch of the proposed stormwater detention facility can be found below (Figure 10). KCRTS output containing “Compare Flow Duration” files and other model results can be found in Appendix E. While there are landslide hazard areas adjacent to the project, the project is not located within those areas and therefore is not required to use a safety factor when designing the stormwater detention facility (SWDM, 2009). Table 4 below compares the pre-developed condition discharge to the proposed condition site discharge from the flow control facility. Table 4: Pre-developed and Proposed Controlled Flow Comparison Talbot Substation Stormwater DesignDrawn by Taylor Hoffman, EIT11/16/2016 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 13 4.5 Water Quality System As mentioned above, stormwater water quality facilities are not required. SPCC facilities will be placed where necessary. 5 Conveyance System Analysis and Design During field observations, two four-inch outlet pipes and catch basins were observed at the project area within the substation fence line at the northern and southern edges of the substation. No further analysis was performed on the existing conveyance system. The proposed stormwater conveyance system was designed to meet the conveyance requirements discussed in Section 4.3 of this report and was analyzed using the Rational Method and XP-SWMM. The Rational Method was used to assess the capacity of the pipes within the conveyance system as required by the 2009 SWDM. XP-SWMM was then used to demonstrate that the pipe system structures contain the hydraulic grade line for the 25-year rainfall event as required by the 2009 SWDM. The Rational Method conservatively calculates runoff flows based on basin area, rainfall intensity, and a runoff coefficient specific to land cover. Runoff flows into each catch basin were calculated for the 25-year event, and a water balance was performed to estimate the flows which would need to be conveyed in each pipe. When the flows were compared to the proposed conveyance system design pipe capacities, all proposed pipes were sized appropriately to convey the 25-year event flows. In XP-SWMM, conveyance system pipes were designed and modeled as 8-inch or 12 inch high density polyethylene (HDPE) pipe or perforated PVC pipe. Catch basins in the conveyance system were either Type 1 or type 1L. The conveyance system was designed to route runoff from the substation, SPCC curb areas, and control house roof toward the south side of the substation, where a pipe outfalls to the proposed detention pond. Slopes of all proposed pipes in the conveyance system were modeled as 0.5%. Compliance with the requirements discussed in Section 4.3 was assessed by routing 25- and 100-year rainfall events through the XP-SWMM model. During the 25-year event, all structures appeared to maintain over 6 inches of freeboard in the model. Additionally, the hydraulic grade line was contained within the conveyance pipes. The conveyance system did not flood during the 100-year event. Model output can be found in Appendix E. 6 Special Reports and Studies No special reports or studies have been prepared for this project. 7 Other Permits Table 5 below lists additional permits required for the project area and their effects on the stormwater design. Technical Information Report Talbot Substation Stormwater Support 14 | November 16, 2016 Table 5: Additional Project Permit Requirements Permit Agency Effects on Stormwater Design TBD TBD TBD TBD TBD TBD 8 CSWPPP Analysis and Design A CSWPPP has been developed for the project and is located in Appendix F. 8.1 ESC Plan Analysis and Design The following ESC best management measures will be employed at the project area, as shown on the TESC plans and discussed in the CSWPPP: 8.1.1 Clearing Limits To protect adjacent properties and reduce the volume of soil exposed to construction, construction limits will be clearly marked where necessary before construction begins. The construction of the proposed stormwater detention pond and paving of a small portion of the existing access road will be the only ground disturbing activity occurring outside of the substation fence. Natural vegetation and topsoil at the project area shall be retained to the maximum extent feasible. High visibility fence and silt fence BMPs will be used around the perimeter of the project area so that disturbance is kept to a minimum outside the work area. 8.1.2 Cover Measures As the project is located west of the Cascade Mountain Crest, no soils shall remain exposed and unworked for more than seven days during the dry season (May 1 to September 30) and two days during the wet season (October 1 to April 30). Between these times, exposed soils stored aboveground shall be protected with straw, wood fiber mulch, compost, plastic sheeting, or equivalent. Regardless of time, all soils shall be stabilized at the end of the shift before a holiday or weekend, and if needed, based on weather forecasts. Any areas expected to remain unworked for greater than 30 days must be seeded or sodded (King County, 1998). During the wet season, soil stockpiles with slopes greater than or equal to 3H:1V, or with over ten feet of vertical relief must be covered if they will remain unworked for over 12 hours. During the wet season sufficient cover materials to stabilize all disturbed areas must be stockpiled on site, and the Wet Season Provisions of Section D.5.S of the King County Erosion and Sediment Control Standards must be followed (King County, 1998). Permanent stabilization will be achieved by placement of yard rock within the substation, and seeding at the proposed stormwater detention pond. 8.1.3 Perimeter Protection Vegetation and slope characteristics vary within the project area. The eastern edge of the project area is elevated and there is no risk contaminated stormwater will exit the project site in that area. The proposed stormwater detention pond and its outlet structure will be installed along the southern edge of the project area. Silt fence will be installed in this area to ensure no contaminated stormwater exits the project area. Silt fencing will Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 15 extend along the existing access road to its intersection with Puget Drive Southeast to prevent sediment generated from the proposed paving activities from exiting the project site. Concrete will be poured on site for proposed electrical equipment foundations within the substation. All concrete at the project area will be handled such that no cementitious material will enter stormwater runoff. Handling procedures are detailed on the TESC plans. 8.1.4 Traffic Area Stabilization The project area will be accessed from the existing access road located on the southern edge of the substation. This access road is a stabilized surface and does not require additional stabilization. Proposed stormwater detention pond construction and access road paving will occur from the existing access road. 8.1.5 Sediment Retention The proposed stormwater detention pond will be retrofitted as a temporary sediment storage facility for the duration of the project. All open grate catch basins and inlets located at the project area will be protected with storm drain inlet protection in order to prevent sediment contamination from entering the conveyance system. The sediment pond must have adequate surface area as defined in Section D.4.5.2 of the King County Erosion and Sediment Control Standards (King County, 1998). Required Pond Surface Area at top of Riser - SA = 2 x Q2/0.00096 Proposed 2-year Peak Flow - Q2= 0.092 Required SA = 192 Square Feet Provided Surface Area: ~ 16,000 Square Feet 8.1.6 Surface Water Collection Outlet protection will be installed at the outlet of the proposed stormwater detention pond before stormwater is routed through the facility. 8.1.7 Dewatering Control Dewatering is not anticipated at the project site, as groundwater was not encountered during field activities performed by GeoEngineers (GeoEngineers, 2016). 8.1.8 Dust Control Wind transport of soils is not anticipated at the project site. Exposed soils will be stabilized and will not remain exposed for long periods. 8.1.9 Flow Control The project area triggers Core Requirement #3: Flow Control. The proposed stormwater detention pond will be retrofitted to serve as a sediment pond during construction. During this period, the hydraulic control structure and pond will continue to function as flow control facility’s and restrict flow rates exiting the site to acceptable limits. Technical Information Report Talbot Substation Stormwater Support 16 | November 16, 2016 8.2 CSWPPP Plan Design The following ESC best management measures will be employed at the project area, as shown on the TESC plans and discussed in the CSWPPP: • High Visibility Plastic Fence o High visibility plastic fence will be used around the perimeter of the substation and access road to clearly mark the proposed limits of construction. This will prevent unnecessary disturbance of existing vegetation and soils. • Silt Fence o Silt fence will be placed along the southern border of the existing access road to prevent sediment contaminated stormwater generated from the construction of the proposed stormwater detention pond and paving of the existing access road from exiting the project site. Silt fence will also serve to delineate the construction limits on the southern boundary of the project area • Temporary Sediment Pond o The proposed stormwater detention pond will be retrofitted as a temporary sediment pond. It will serve to retain sediment generated within the substation fence by placement of the proposed foundations, yard rock, and electrical components. The sediment pond will prevent sediment from exiting the project area. Sediment retention facilities are required whenever the project area exceeds three acres. Flow control is also required for the project, and the proposed stormwater detention pond will continue to regulate outflows through its control structure while it is being used as a temporary sediment retention facility. • Catch Basin Insert o Catch basin inserts will be placed on all catch basins within the substation fence line. They will be used to prevent sediment generated by work within the substation fence line from entering the proposed stormwater conveyance system and being transported downstream. • Outlet Protection o Outlet protection will be used at the outlet of the proposed stormwater detention pond. It will prevent scouring and erosion due to stormwater discharges exiting the pond. This is a permanent BMP which will be retained in place after construction is complete. Updates to the SWPPP may be requested by King County at any time during project construction if the County determines that pollutants generated on the construction site have the potential to contaminate surface, storm, or ground water. Technical Information Report Talbot Substation Stormwater Support November 16, 2016 | 17 9 Bond Quantities, Facility Summaries, and Declaration of Covenant 9.1 Bond Quantities Worksheet The Bond Quantities Worksheet is located in Appendix G. 9.2 Flow Control and Water Quality Facility Summary Sheet and Sketch The Flow Control and Water Quality Facility Summary Sheet and Sketch is located in Appendix G. 9.3 Declaration of Covenant for Privately Maintained Flow Control and WQ Facilities Declaration of Covenant is not required for proposed privately maintained flow control facilities. 9.4 Declaration of Covenant for Privately Maintained Flow Control BMPs There are no flow control BMPs present at the project area. 10 Operations and Maintenance Manual A copy of the Operations and Maintenance Manual, along with the Maintenance Requirements for Flow Control, Conveyance, and WQ Facilities is located in Appendix H. 11 References City of Renton. (2010). City of Renton Amendments to the King County Surface Water Design Manual. Renton: City of Renton. King County. (2009). Surface Water Design Manual. Seattle: King County . 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Substation locatedsoutheast of mapextent Substation locatednortheast of mapextent. KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual 1/9/2009 KING COUNTY, WASHINGTON SURFACE WATER DESIGN MANUAL REFERENCE 8-B OFFSITE ANALYSIS DRAINAGE SYSTEM TABLE 1/9/2009 OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT #2 Basin: Subbasin Name: Subbasin Number: Symbol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from site discharge Existing Problems Potential Problems Observations of field inspector, resource reviewer, or resident see map Type: sheet flow, swale, stream, channel, pipe, pond; Size: diameter, surface area drainage basin, vegetation, cover, depth, type of sensitive area, volume % ¼ ml = 1,320 ft. constrictions, under capacity, ponding, overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, incision, other erosion tributary area, likelihood of problem, overflow pathways, potential impacts Duwamish RiverProject Area1Pink FillBlue FillLandslide HazardErosion HazardAdjacentAdjacentNone documentedNone observedNone documentedNone observedIncreasederosion andbank failure riskYellow FillSteep SlopeAdjacentNone documentedNone observed 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL Lake Desire Shady Lake (Mud Lake) Panther Lake Lake Youngs Lake Washington Bl ack Riv e r Gr ee n Ri ver Ce darRi v erUV900 UV167 UV515 UV169 UV900 UV169 UV167BN IncBN IncBBNNIInnccSSEERReennttoonnIIssssaaqquuaahh RRdd RReennttoonnMMaapplleeVVaalllleeyyRRdd MMaapplleeVVaalllleeyyHHwwyy 110088tthhAAvveeSSEESSWWSSuunnsseettBBllvvdd RRaaii nnii eerrAAvveeNNNE 3rd S t NE 3rd S t SW 43rd StSW 43rd St SSEE CC aarrrrRRdd NE 4th StNE 4th St SSEERReennttoonn MMaapplleeVVaalllleeyyRRddLLooggaannAAvveeNN SR 515SR 515PPaarrkkAAvveeNNOOaakkeessddaalleeAAvveeSSWWSSuunnsseettBBllvvddNNEE DDuuvvaallllAAvveeNNEEI-405 FWYI-405 FWY II--440055FFWWYYSR 167SR 167114400tthh WWaayySS EENNEE2277tthhSStt 115566tthhAAvveeSSEEUUnniioonnAAvveeNNEE111166tthhAAvveeSSEESW 7th StSW 7th St N 8th StN 8th St PP uuggeettDD rrSSEE RR eennttoonnAAvvee SS SSWW 2277tthhSStt BBeennssoonnRRddSSWWiilllliiaammssAAvveeSSMMoonnrrooeeAAvveeNNEESE 128th StSE 128th St II nntt eerr uurr bbaannAAvveeSS HHooqquuiiaammAAvveeNNEE8844tthhAAvveeSSSSEEPPeett rr oovviitt sskkyyRRddEEVVaalllleeyyHHwwyySE 192nd StSE 192nd St SE 60th StSE 60th St TTaallbboottRRddSSRRee nntt oo nn AAvveeSS116644tthhAAvveeSSEESE 208th StSE 208th St SE 72nd StSE 72nd St RR aaiinniieerr AAvvee SS 111166tthhAAvveeSSEES 128th StS 128th St NNeewwccaassttlleeWWaayy SS 221122tthh SStt SS118800tthh SStt CCooaall CCrreeeekkPPkkwwyySSEESW 41st StSW 41st St 114400tthhAAvveeSSEE112288tthhAAvveeSSEE6688tthhAAvveeSSSSEE 116688tthhSStt NE 12th StNE 12th St BBee aa ccoonn AAvv ee SSFFoorreessttDDrr SSEE SSEE116644tthhSStt 114488tthhAAvveeSSEESSEEMMaayy VVaalllleeyyRRdd SSEE JJoonneess RRdd SS EE 22 00 44tt hh WW aayySW 34th StSW 34th St SE 144th StSE 144th St 114488tthhAAvveeSSEE115544tthhPP llSS EELL aa kk ee WWaa sshhii nnggtt oonnBBll vvddNNEEddmmoonnddssAAvveeNNEEAAbbeerrddeeeennAAvveeNNEEEEMM eerrcceerrWWaayyWWeessttVVaalllleeyyHHwwyyEast Valley RdEast Valley Rd,§-405 ,§-405 ,§-405 μ 0 12 Miles Flow Control Application Map Reference 11-A Date: 01/09/2014 Flow Control Standards Peak Rate Flow Control Standard (Existing Site Conditions) Flow Control Duration Standard (Existing Site Conditions) Flow Control Duration Standard (Forested Conditions) Flood Problem Flow Unincorporated King County Flow Control Standards Renton City Limits Potential Annexation Area Project Location Appendix E Stormwater Model Input & Output 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL KCRTS Pre-developed and Developed Land Use Areas Pre-developed and Developed Land Use Areas Model Input Pre-developed Condition Land Use Areas Land Use Type Area (ac) Impervious 0.00 Till Forest 5.89 Developed Condition Land Use Areas Land Use Type Area (ac) Impervious 3.83 Till Grass 2.06 Total Area: 5.89 Maximum positive excursion = 0.008 cfs (6.7%) occurring at 0.120 cfs on the Base Data (psetalbotpredev_020816.tsf) and at 0.128 cfs on the New Data (pserdout_020816.tsf). Maximum negative excursion = 0.019 cfs (-19.0%) occurring at 0.099 cfs on the Base Data (psetalbotpredev_020816.tsf) and at 0.080 cfs on the New Data (pserdout_020816.tsf). Pond Design Results Retention/Detention Facility Type of Facility: Detention Pond Side Slope: 2.00 H:1V Pond Bottom Length: 241.81 ft Pond Bottom Width: 27.00 ft Pond Bottom Area: 6529. sq. ft Top Area at 1 ft. FB: 16155. sq. ft 0.371 acres Effective Storage Depth: 7.00 ft Stage 0 Elevation: 425.50 ft Storage Volume: 73876. cu. ft 1.696 ac-ft Riser Head: 7.00 ft Riser Diameter: 12.00 inches Number of orifices: 3 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 1.15 0.095 2 4.85 2.13 0.180 6.0 3 6.10 2.00 0.103 4.0 Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation Surf Area (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) (sq. ft) 0.00 425.50 0. 0.000 0.000 0.00 6529. 0.01 425.51 65. 0.001 0.004 0.00 6540. 0.02 425.52 131. 0.003 0.006 0.00 6551. 0.04 425.54 262. 0.006 0.007 0.00 6572. 0.05 425.55 328. 0.008 0.008 0.00 6583. 0.06 425.56 394. 0.009 0.009 0.00 6594. 0.07 425.57 460. 0.011 0.010 0.00 6604. 0.08 425.58 526. 0.012 0.010 0.00 6615. 0.10 425.60 658. 0.015 0.011 0.00 6637. 0.23 425.73 1530. 0.035 0.017 0.00 6777. 0.37 425.87 2490. 0.057 0.022 0.00 6929. 0.51 426.01 3470. 0.080 0.026 0.00 7082. 0.64 426.14 4400. 0.101 0.029 0.00 7224. 0.78 426.28 5422. 0.124 0.032 0.00 7377. 0.92 426.42 6466. 0.148 0.034 0.00 7532. 1.06 426.56 7531. 0.173 0.037 0.00 7687. 1.19 426.69 8540. 0.196 0.039 0.00 7831. 1.33 426.83 9647. 0.221 0.041 0.00 7987. 1.47 426.97 10776. 0.247 0.043 0.00 8144. 1.61 427.11 11928. 0.274 0.045 0.00 8302. 1.74 427.24 13016. 0.299 0.047 0.00 8448. 1.88 427.38 14210. 0.326 0.049 0.00 8607. 2.02 427.52 15426. 0.354 0.051 0.00 8766. 2.15 427.65 16576. 0.381 0.053 0.00 8915. 2.29 427.79 17835. 0.409 0.054 0.00 9075. 2.43 427.93 19117. 0.439 0.056 0.00 9236. 2.57 428.07 20421. 0.469 0.057 0.00 9398. 2.70 428.20 21653. 0.497 0.059 0.00 9549. 2.84 428.34 23001. 0.528 0.060 0.00 9712. 2.98 428.48 24372. 0.560 0.062 0.00 9875. 3.12 428.62 25766. 0.592 0.063 0.00 10040. 3.25 428.75 27081. 0.622 0.065 0.00 10193. 3.39 428.89 28520. 0.655 0.066 0.00 10358. 3.53 429.03 29981. 0.688 0.067 0.00 10524. 3.66 429.16 31359. 0.720 0.069 0.00 10679. 3.80 429.30 32866. 0.755 0.070 0.00 10846. 3.94 429.44 34396. 0.790 0.071 0.00 11014. 4.08 429.58 35950. 0.825 0.072 0.00 11182. 4.21 429.71 37414. 0.859 0.074 0.00 11339. 4.35 429.85 39013. 0.896 0.075 0.00 11509. 4.49 429.99 40637. 0.933 0.076 0.00 11679. 4.63 430.13 42284. 0.971 0.077 0.00 11850. 4.76 430.26 43835. 1.006 0.078 0.00 12010. 4.85 430.35 44920. 1.031 0.079 0.00 12120. 4.87 430.37 45163. 1.037 0.080 0.00 12145. 4.89 430.39 45406. 1.042 0.084 0.00 12170. 4.92 430.42 45772. 1.051 0.090 0.00 12207. 4.94 430.44 46016. 1.056 0.098 0.00 12231. 4.96 430.46 46261. 1.062 0.108 0.00 12256. 4.98 430.48 46507. 1.068 0.120 0.00 12281. 5.00 430.50 46752. 1.073 0.128 0.00 12305. 5.03 430.53 47122. 1.082 0.132 0.00 12342. 5.05 430.55 47369. 1.087 0.135 0.00 12367. 5.19 430.69 49113. 1.127 0.153 0.00 12541. 5.32 430.82 50754. 1.165 0.167 0.00 12702. 5.46 430.96 52544. 1.206 0.180 0.00 12877. 5.60 431.10 54359. 1.248 0.191 0.00 13052. 5.74 431.24 56199. 1.290 0.201 0.00 13228. 5.87 431.37 57929. 1.330 0.211 0.00 13392. 6.01 431.51 59816. 1.373 0.220 0.00 13569. 6.10 431.60 61043. 1.401 0.226 0.00 13683. 6.12 431.62 61317. 1.408 0.228 0.00 13709. 6.14 431.64 61591. 1.414 0.231 0.00 13734. 6.16 431.66 61866. 1.420 0.237 0.00 13760. 6.18 431.68 62141. 1.427 0.244 0.00 13785. 6.20 431.70 62417. 1.433 0.252 0.00 13811. 6.23 431.73 62832. 1.442 0.262 0.00 13849. 6.25 431.75 63109. 1.449 0.272 0.00 13874. 6.27 431.77 63387. 1.455 0.280 0.00 13900. 6.40 431.90 65205. 1.497 0.303 0.00 14066. 6.54 432.04 67187. 1.542 0.323 0.00 14246. 6.68 432.18 69194. 1.588 0.341 0.00 14426. 6.82 432.32 71226. 1.635 0.357 0.00 14606. 6.95 432.45 73136. 1.679 0.372 0.00 14775. 7.00 432.50 73876. 1.696 0.377 0.00 14840. 7.10 432.60 75367. 1.730 0.696 0.00 14970. 7.20 432.70 76870. 1.765 1.270 0.00 15100. 7.30 432.80 78387. 1.800 2.010 0.00 15231. 7.40 432.90 79916. 1.835 2.810 0.00 15362. 7.50 433.00 81459. 1.870 3.100 0.00 15493. 7.60 433.10 83015. 1.906 3.360 0.00 15625. 7.70 433.20 84584. 1.942 3.610 0.00 15757. 7.80 433.30 86167. 1.978 3.830 0.00 15889. 7.90 433.40 87762. 2.015 4.050 0.00 16022. 8.00 433.50 89371. 2.052 4.250 0.00 16155. 8.10 433.60 90993. 2.089 4.440 0.00 16288. 8.20 433.70 92629. 2.126 4.630 0.00 16422. 8.30 433.80 94278. 2.164 4.800 0.00 16556. 8.40 433.90 95940. 2.202 4.970 0.00 16690. 8.50 434.00 97616. 2.241 5.140 0.00 16825. 8.60 434.10 99305. 2.280 5.300 0.00 16960. 8.70 434.20 101008. 2.319 5.450 0.00 17095. 8.80 434.30 102724. 2.358 5.600 0.00 17230. 8.90 434.40 104454. 2.398 5.750 0.00 17366. Hyd Inflow Outflow Peak Storage Target Calc Stage Elev (Cu-Ft) (Ac-Ft) 1 2.25 0.47 1.05 7.16 432.66 76281. 1.751 2 1.11 ******* 0.36 6.80 432.30 71008. 1.630 3 1.12 ******* 0.26 6.23 431.73 62802. 1.442 4 1.18 ******* 0.17 5.37 430.87 51439. 1.181 5 1.34 ******* 0.28 6.27 431.77 63431. 1.456 6 0.70 ******* 0.09 4.92 430.42 45833. 1.052 7 0.91 ******* 0.08 4.57 430.07 41528. 0.953 8 0.99 ******* 0.07 3.37 428.87 28288. 0.649 ---------------------------------- Route Time Series through Facility Inflow Time Series File:psetalbotdev_020816.tsf Outflow Time Series File:PSErdout_020816 Inflow/Outflow Analysis Peak Inflow Discharge: 2.25 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 1.04 CFS at 10:00 on Jan 9 in Year 8 Peak Reservoir Stage: 7.16 Ft Peak Reservoir Elev: 432.66 Ft Peak Reservoir Storage: 76281. Cu-Ft : 1.751 Ac-Ft 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual 1/9/2009 KING COUNTY, WASHINGTON SURFACE WATER DESIGN MANUAL REFERENCE 8-D FLOW CONTROL AND WATER QUALITY FACILITY SUMMARY SHEET AND SKETCH KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual 1/9/2009 1 STORMWATER FACILITY SUMMARY SHEET DDES Permit Number__________________ (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Overview: Project Name _______________________________________________________Date___________________ Downstream Drainage Basins Major Basin Name _____________________________ Immediate Basin Name __________________________ Flow Control: Flow Control Facility Name/Number ________________________________ Facility Location________________________________________________________________________ ___ If none, Flow control provided in regional/shared facility (give location)___________________________________ No flow control required_____________ Exemption number _______________________________ General Facility Information: Type/Number of detention facilities: Type/Number of infiltration facilities: ______ ponds ______ ponds ______ vaults ______ tanks ______ tanks ______ trenches Control Structure Location _____________________________________________________________________ Type of Control Structure ______________________________ Number of Orifices/Restrictions _____________ Size of Orifice/Restriction: No. 1 ________________ No. 2 ________________ No. 3 ________________ No. 4 ________________ Flow Control Performance Standard _________________________________ 1 Talbot Substation Stormwater Support September 28, 2016 Duwamish River Project Area Subbasin Stormwater Detention Pond Southeastern corner of Talbot Substation 1 Control structure located on southern side of detention pond. Match forested condition for flows from 50% of the 2 year up to 100% of the 50-year 2.13 inches 1.15 inches 12 inch diameter riser structure 3 2.00 inches KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual 1/9/2009 2 Live Storage Volume __________________ Depth _______________ Volume Factor of Safety ________________ Number of Acres Served ____________________ Number of Lots ____________________ Dam Safety Regulations (Washington State Department of Ecology) Reservoir Volume above natural grade ________________ Depth of Reservoir above natural grade _______________ Facility Summary Sheet Sketch All detention, infiltration and water quality facilities must include a detailed sketch. (11"x17" reduced size plan sheets may be used) 73,876 Cubic Feet 7.0 Ft (effect. storage) 1 73,876 above excavated grade. 27,124 above natural grade. 7.5 above excavated grade. 2.5 above natural grade. 5.89 acres Proposed Discharge Point No access to pond from inside the substation Proposed Stormwater Detention Pond Control Structure Location Pond Access Road PATH: G:\PROJECTS\WASHINGTON\PUGET_SOUND_ENERGY_007022\TALBOT_STORMWATER_SUPPORT_269966\MAP_DOCS\DRAFT\TIR FIGURES\APPENDIX G FACILTY SKETCH.MXD - USER: TAHOFFMA - DATE: 11/16/2016 TALBOT STORMWATER SUPPORT APPENDIX G FLOW CONTROL FACILITY SKETCH STORMWATER TIR 0150Feet O DATA SOURCE: City of Renton, King County (2016) LEGEND Project Area Contours - 10 ft Interval Proposed Control Structure Proposed Flow Path Proposed Drainage Infrastructure Proposed Detention Pond Proposed Access Road 2009 Surface Water Design Manual Amendment City of Renton CITY OF RENTON AMENDMENTS TO THE KING COUNTY SURFACE WATER DESIGN MANUAL REFERENCE 8-H BOND QUANTITIES WORKSHEET Site Improvement Bond Quantity WorksheetOriginal bond computations prepared by:Name:Date:PE Registration Number:Tel. #:Firm Name:Address:Project No: Stabilization/Erosion Sediment Control (ESC) (A)Existing Right-of-Way Improvements (B)Future Public Road Improvements & Drainage Facilities (C)Private Improvements (D)Construction Bond* Amount (A+B+C+D) = TOTAL (T)Minimum bond* amount is $1000.Maintenance/Defect Bond* TotalNAME OF PERSON PREPARING BOND* REDUCTION:Date:* NOTE:The word "bond" as used in this document means any financial guarantee acceptable to the City of Renton.** NOTE: All prices include labor, equipment, materials, overhead and profit. Prices are from RS Means data adjusted for the Seattle areaor from local sources if not included in the RS Means database.REQUIRED BOND* AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY RDSD-$ -$ -$ (B+C) x 0.20 =-$ ROAD IMPROVEMENTS & DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTSPERFORMANCE BOND*,**AMOUNTPUBLIC ROAD & DRAINAGE MAINTENANCE/DEFECT BOND*,**-$ -$ Page 1 of 1REF 8-H BOND QUANTITY WORKSHEET.xlsUnit prices updated: 2/12/02Version: 4/22/02Report Date: 1/19/2010 Site Improvement Bond Quantity WorksheetExisting Future Public PrivateRight-of-Way Road Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostGENERAL ITEMSNo.Backfill & Compaction- embankment GI - 1 5.62$ CY0.00 0.00 0.00 0.00Backfill & Compaction- trench GI - 2 8.53$ CY0.00 0.00 0.00 0.00Clear/Remove Brush, by hand GI - 3 0.36$ SY 0.00 0.00 0.00 0.00Clearing/Grubbing/Tree Removal GI - 4 8,876.16$ Acre 0.00 0.00 0.00 0.00Excavation - bulk GI - 5 1.50$ CY0.00 0.00 0.00 0.00Excavation - Trench GI - 6 4.06$ CY0.00 0.00 0.00 0.00Fencing, cedar, 6' high GI - 7 18.55$ LF 0.00 0.00 0.00 0.00Fencing, chain link, vinyl coated, 6' high GI - 8 13.44$ LF 0.00 0.00 0.00 0.00Fencing, chain link, gate, vinyl coated, 20GI - 9 1,271.81$ Each 0.00 0.00 0.00 0.00Fencing, split rail, 3' high GI - 10 12.12$ LF 0.00 0.00 0.00 0.00Fill & compact - common barrow GI - 11 22.57$ CY0.00 0.00 0.00 0.00Fill & compact - gravel base GI - 12 25.48$ CY0.00 0.00 0.00 0.00Fill & compact - screened topsoil GI - 13 37.85$ CY0.00 0.00 0.00 0.00Gabion, 12" deep, stone filled mesh GI - 14 54.31$ SY 0.00 0.00 0.00 0.00Gabion, 18" deep, stone filled mesh GI - 15 74.85$ SY 0.00 0.00 0.00 0.00Gabion, 36" deep, stone filled mesh GI - 16 132.48$ SY 0.00 0.00 0.00 0.00Grading, fine, by hand GI - 17 2.02$ SY 0.00 0.00 0.00 0.00Grading, fine, with grader GI - 18 0.95$ SY 0.00 0.00 0.00 0.00Monuments, 3' long GI - 19 135.13$ Each 0.00 0.00 0.00 0.00Sensitive Areas Sign GI - 20 2.88$ Each 0.00 0.00 0.00 0.00Sodding, 1" deep, sloped ground GI - 21 7.46$ SY 0.00 0.00 0.00 0.00Surveying, line & grade GI - 22 788.26$ Day0.00 0.00 0.00 0.00Surveying, lot location/lines GI - 23 1,556.64$ Acre 0.00 0.00 0.00 0.00Traffic control crew ( 2 flaggers ) GI - 24 85.18$ HR0.00 0.00 0.00 0.00Trail, 4" chipped wood GI - 25 7.59$ SY 0.00 0.00 0.00 0.00Trail, 4" crushed cinder GI - 26 8.33$ SY 0.00 0.00 0.00 0.00Trail, 4" top course GI - 27 8.19$ SY 0.00 0.00 0.00 0.00Wall, retaining, concrete GI - 28 44.16$ SF 0.00 0.00 0.00 0.00Wall, rockery GI - 29 9.49$ SF 0.00 0.00 0.00 0.00Page 2 of 7 SUBTOTAL 0.00 0.00 0.00 0.00Quantity Completed (Bond Reduction)*REF 8-H BOND QUANTITY WORKSHEET.xlsUnit prices updated: 2/12/02Version: 4/22/02Report Date: 1/19/2010 Site Improvement Bond Quantity WorksheetExisting Future Public PrivateBond Reduction*Right-of-wayRoad Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostROAD IMPROVEMENTNo.AC Grinding, 4' wide machine < 1000sy RI - 1 23.00$ SY 0.00 0.00 0.00 0.00AC Grinding, 4' wide machine 1000-2000sRI - 2 5.75$ SY 0.00 0.00 0.00 0.00AC Grinding, 4' wide machine > 2000sy RI - 3 1.38$ SY 0.00 0.00 0.00 0.00AC Removal/Disposal/Repair RI - 4 41.14$ SY 0.00 0.00 0.00 0.00Barricade, type I RI - 5 30.03$ LF 0.00 0.00 0.00 0.00Barricade, type III ( Permanent ) RI - 6 45.05$ LF 0.00 0.00 0.00 0.00Curb & Gutter, rolled RI - 7 13.27$ LF 0.00 0.00 0.00 0.00Curb & Gutter, vertical RI - 8 9.69$ LF 0.00 0.00 0.00 0.00Curb and Gutter, demolition and disposal RI - 9 13.58$ LF 0.00 0.00 0.00 0.00Curb, extruded asphalt RI - 10 2.44$ LF 0.00 0.00 0.00 0.00Curb, extruded concrete RI - 11 2.56$ LF 0.00 0.00 0.00 0.00Sawcut, asphalt, 3" depth RI - 12 1.85$ LF 0.00 0.00 0.00 0.00Sawcut, concrete, per 1" depth RI - 13 1.69$ LF 0.00 0.00 0.00 0.00Sealant, asphalt RI - 14 0.99$ LF 0.00 0.00 0.00 0.00Shoulder, AC, ( see AC road unit price ) RI - 15 -$ SY 0.00 0.00 0.00 0.00Shoulder, gravel, 4" thick RI - 16 7.53$ SY 0.00 0.00 0.00 0.00Sidewalk, 4" thick RI - 17 30.52$ SY 0.00 0.00 0.00 0.00Sidewalk, 4" thick, demolition and disposaRI - 18 27.73$ SY 0.00 0.00 0.00 0.00Sidewalk, 5" thick RI - 19 34.94$ SY 0.00 0.00 0.00 0.00Sidewalk, 5" thick, demolition and disposaRI - 20 34.65$ SY 0.00 0.00 0.00 0.00Sign, handicap RI - 21 85.28$ Each 0.00 0.00 0.00 0.00Striping, per stall RI - 22 5.82$ Each 0.00 0.00 0.00 0.00Striping, thermoplastic, ( for crosswalk ) RI - 23 2.38$ SF 0.00 0.00 0.00 0.00Striping, 4" reflectorized line RI - 24 0.25$ LF 0.00 0.00 0.00 0.00Page 3 of 7 SUBTOTAL 0.00 0.00 0.00 0.00REF 8-H BOND QUANTITY WORKSHEET.xlsUnit prices updated: 2/12/02Version: 4/22/02Report Date: 1/19/2010 Site Improvement Bond Quantity WorksheetExisting Future Public PrivateBond Reduction*Right-of-wayRoad Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostROAD SURFACING (4" Rock = 2.5 base & 1.5" top course) For '93 KCRS ( 6.5" Rock= 5" base & 1.5" top course)For KCRS '93, (additional 2.5" base) add: RS - 1 3.60$ SY 0.00 0.00 0.00 0.00AC Overlay, 1.5" AC RS - 2 7.39$ SY 0.00 0.00 0.00 0.00AC Overlay, 2" AC RS - 3 8.75$ SY 0.00 0.00 0.00 0.00AC Road, 2", 4" rock, First 2500 SY RS - 4 17.24$ SY 0.00 0.00 0.00 0.00AC Road, 2", 4" rock, Qty. over 2500SY RS - 5 13.36$ SY 0.00 0.00 0.00 0.00AC Road, 3", 4" rock, First 2500 SY RS - 6 19.69$ SY 0.00 0.00 0.00 0.00AC Road, 3", 4" rock, Qty. over 2500 SY RS - 7 15.81$ SY 0.00 0.00 0.00 0.00AC Road, 5", First 2500 SY RS - 8 14.57$ SY 0.00 0.00 0.00 0.00AC Road, 5", Qty. Over 2500 SY RS - 9 13.94$ SY 0.00 0.00 0.00 0.00AC Road, 6", First 2500 SYRS - 1016.76$ SY 0.00 0.00 0.00 0.00AC Road, 6", Qty. Over 2500 SYRS - 1116.12$ SY 0.00 0.00 0.00 0.00Asphalt Treated Base, 4" thickRS - 129.21$ SY 0.00 0.00 0.00 0.00Gravel Road, 4" rock, First 2500 SYRS - 1311.41$ SY 0.00 0.00 0.00 0.00Gravel Road, 4" rock, Qty. over 2500 SYRS - 147.53$ SY 0.00 0.00 0.00 0.00PCC Road, 5", no base, over 2500 SYRS - 1521.51$ SY 0.00 0.00 0.00 0.00PCC Road, 6", no base, over 2500 SYRS - 1621.87$ SY 0.00 0.00 0.00 0.00Thickened EdgeRS - 176.89$ LF 0.00 0.00 0.00 0.00Page 4 of 7 SUBTOTAL 0.00 0.00 0.00 0.00REF 8-H BOND QUANTITY WORKSHEET.xlsUnit prices updated: 2/12/02Version: 4/22/02Report Date: 1/19/2010 Site Improvement Bond Quantity WorksheetExisting Future Public PrivateBond Reduction*Right-of-wayRoad Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostDRAINAGE (CPP = Corrugated Plastic Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.Access Road, R/D D - 1 16.74$ SY 0.00 0.00 0.00 0.00Bollards - fixed D - 2 240.74$ Each 0.00 0.00 0.00 0.00Bollards - removable D - 3 452.34$ Each 0.00 0.00 0.00 0.00* (CBs include frame and lid)CB Type I D - 4 1,257.64$ Each 0.00 0.00 0.00 0.00CB Type IL D - 5 1,433.59$ Each 0.00 0.00 0.00 0.00CB Type II, 48" diameter D - 6 2,033.57$ Each 0.00 0.00 0.00 0.00 for additional depth over 4' D - 7 436.52$ FT 0.00 0.00 0.00 0.00CB Type II, 54" diameter D - 8 2,192.54$ Each 0.00 0.00 0.00 0.00 for additional depth over 4' D - 9 486.53$ FT 0.00 0.00 0.00 0.00CB Type II, 60" diameter D - 10 2,351.52$ Each 0.00 0.00 0.00 0.00 for additional depth over 4' D - 11 536.54$ FT 0.00 0.00 0.00 0.00CB Type II, 72" diameter D - 12 3,212.64$ Each 0.00 0.00 0.00 0.00 for additional depth over 4' D - 13 692.21$ FT 0.00 0.00 0.00 0.00Through-curb Inlet Framework (Add) D - 14 366.09$ Each 0.00 0.00 0.00 0.00Cleanout, PVC, 4" D - 15 130.55$ Each 0.00 0.00 0.00 0.00Cleanout, PVC, 6" D - 16 174.90$ Each 0.00 0.00 0.00 0.00Cleanout, PVC, 8" D - 17 224.19$ Each 0.00 0.00 0.00 0.00Culvert, PVC, 4" D - 18 8.64$ LF 0.00 0.00 0.00 0.00Culvert, PVC, 6" D - 19 12.60$ LF 0.00 0.00 0.00 0.00Culvert, PVC, 8" D - 20 13.33$ LF 0.00 0.00 0.00 0.00Culvert, PVC, 12" D - 21 21.77$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 8" D - 22 17.25$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 12" D - 23 26.45$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 15" D - 24 32.73$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 18" D - 25 37.74$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 24" D - 26 53.33$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 30" D - 27 71.45$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 36" D - 28 112.11$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 48" D - 29 140.83$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 60" D - 30 235.45$ LF 0.00 0.00 0.00 0.00Culvert, CMP, 72" D - 31 302.58$ LF 0.00 0.00 0.00 0.00Page 5 of 7 SUBTOTAL 0.00 0.00 0.00 0.00REF 8-H BOND QUANTITY WORKSHEET.xlsUnit prices updated: 2/12/02Version: 4/22/02Report Date: 1/19/2010 Site Improvement Bond Quantity WorksheetExisting Future Public PrivateBond Reduction*Right-of-wayRoad Improvements ImprovementsDRAINAGE CONTINUED & Drainage FacilitiesQuant.No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostCulvert, Concrete, 8" D - 32 21.02$ LF 0 0 0 0Culvert, Concrete, 12" D - 33 30.05$ LF 0 0 0 0Culvert, Concrete, 15" D - 34 37.34$ LF 0 0 0 0Culvert, Concrete, 18" D - 35 44.51$ LF 0 0 0 0Culvert, Concrete, 24" D - 36 61.07$ LF 0 0 0 0Culvert, Concrete, 30" D - 37 104.18$ LF 0 0 0 0Culvert, Concrete, 36" D - 38 137.63$ LF 0 0 0 0Culvert, Concrete, 42" D - 39 158.42$ LF 0 0 0 0Culvert, Concrete, 48" D - 40 175.94$ LF 0 0 0 0Culvert, CPP, 6" D - 41 10.70$ LF 0 0 0 0Culvert, CPP, 8" D - 42 16.10$ LF 0 0 0 0Culvert, CPP, 12" D - 43 20.70$ LF 0 0 0 0Culvert, CPP, 15" D - 44 23.00$ LF 0 0 0 0Culvert, CPP, 18" D - 45 27.60$ LF 0 0 0 0Culvert, CPP, 24" D - 46 36.80$ LF 0 0 0 0Culvert, CPP, 30" D - 47 48.30$ LF 0 0 0 0Culvert, CPP, 36" D - 48 55.20$ LF 0 0 0 0Ditching D - 49 8.08$ CY00 0 0Flow Dispersal Trench (1,436 base+) D - 50 25.99$ LFFrench Drain (3' depth) D - 51 22.60$ LF 0 0 0 0Geotextile, laid in trench, polypropylene D - 52 2.40$ SY 0 0 0 0Infiltration pond testing D - 53 74.75$ HR00 0 0Mid-tank Access Riser, 48" dia, 6' deep D - 54 1,605.40$ Each 0 0 0 0Pond Overflow SpillwayD - 55 14.01$ SY 0 0 0 0Restrictor/Oil Separator, 12" D - 56 1,045.19$ Each 0 0 0 0Restrictor/Oil Separator, 15" D - 57 1,095.56$ Each 0 0 0 0Restrictor/Oil Separator, 18" D - 58 1,146.16$ Each 0 0 0 0Riprap, placed D - 59 39.08$ CY00 0 0Tank End Reducer (36" diameter) D - 60 1,000.50$ Each 0 0 0 0Trash Rack, 12" D - 61 211.97$ Each 0 0 0 0Trash Rack, 15" D - 62 237.27$ Each 0 0 0 0Trash Rack, 18" D - 63 268.89$ Each 0 0 0 0Trash Rack, 21" D - 64 306.84$ Each 0 0 0 0Page 6 of 7 SUBTOTAL00 0 0REF 8-H BOND QUANTITY WORKSHEET.xlsUnit prices updated: 2/12/02Version: 4/22/02Report Date: 1/19/2010 Site Improvement Bond Quantity WorksheetExisting Future Public PrivateBond Reduction*Right-of-wayRoad Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Price Quant. Cost Quant. Cost Complete CostPARKING LOT SURFACINGNo.2" AC, 2" top course rock & 4" borrow PL - 1 15.84$ SY 0 0 0 02" AC, 1.5" top course & 2.5" base coursPL - 2 17.24$ SY 0 0 0 04" select borrow PL - 3 4.55$ SY 0 0 0 01.5" top course rock & 2.5" base course PL - 4 11.41$ SY 0 0 0 0WRITE-IN-ITEMS(Such as detention/water quality vaults.)No.WI - 1 Each 0 0.00 0.00 0.00WI - 2 SY 0 0.00 0.00 0.00WI - 3 CY0 0.00 0.00 0.00WI - 4 LF 0 0.00 0.00 0.00WI - 5 FT 0 0.00 0.00 0.00WI - 6 0 0.00 0.00 0.00WI - 7 0 0.00 0.00 0.00WI - 8 0 0.00 0.00 0.00WI - 9 0 0.00 0.00 0.00WI - 100 0.00 0.00 0.00SUBTOTAL 0.00 0.00 0.00 0.00SUBTOTAL (SUM ALL PAGES):0.00 0.00 0.00 0.0030% CONTINGENCY & MOBILIZATION:0.00 0.00 0.00 0.00 GRANDTOTAL: 0.00 0.00 0.00 0.00COLUMN: B C D EPage 7 of 7REF 8-H BOND QUANTITY WORKSHEET.xlsUnit prices updated: 2/12/02Version: 4/22/02Report Date: 1/19/2010 5IJTQBHFJOUFOUJPOBMMZMFGUCMBOL KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 1/9/2009 KING COUNTY, WASHINGTON SURFACE WATER DESIGN MANUAL APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE AND WQ FACILITIES KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-1 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES This appendix contains the maintenance requirements for the following typical stormwater control facilities and components: No. 1 – Detention Ponds (p. A-2) No. 2 – Infiltration Facilities (p. A-3) No. 3 – Detention Tanks and Vaults (p. A-5) No. 4 – Control Structure/Flow Restrictor (p. A-7) No. 5 – Catch Basins and Manholes (p. A-9) No. 6 – Conveyance Pipes and Ditches (p. A-11) No. 7 – Debris Barriers (e.g., Trash Racks) (p. A-12) No. 8 – Energy Dissipaters (p. A- 13) No. 9 – Fencing (p. A-14) No. 10 – Gates/Bollards/Access Barriers (p. A-15) No. 11 – Grounds (Landscaping) (p. A-16) No. 12 – Access Roads (p. A-17) No. 13 – Basic Biofiltration Swale (grass) (p. A-18) No. 14 – Wet Biofiltration Swale (p. A-19) No. 15 – Filter Strip (p. A-20) No. 16 – Wetpond (p. A-21) No. 17 – Wetvault (p. A-23) No. 18 – Stormwater Wetland (p. A-24) No. 19 – Sand Filter Pond (p. A-26) No. 20 – Sand Filter Vault (p. A-28) No. 21 – Stormfilter (Cartridge Type) (p. A-30) No. 22 – Baffle Oil/Water Separator (p. A-32) No. 23 – Coalescing Plate Oil/Water Separator (p. A-33) No. 24 – Catch Basin Insert (p. A-35) Relevant facilities and components have been outlined in red. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-2 NO. 1 – DETENTION PONDS Maintenance Component Defect or Problem Conditions When Maintenance Is Needed Results Expected When Maintenance Is Performed Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Top or Side Slopes of Dam, Berm or Embankment Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Sediment accumulation Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth; pond reseeded if necessary to control erosion. Storage Area Liner damaged (If Applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. Emergency Overflow/Spillway Rock missing Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil on the spillway. Spillway restored to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-3 NO. 2 – INFILTRATION FACILITIES Maintenance Component Defect or Problem Conditions When Maintenance Is Needed Results Expected When Maintenance Is Performed Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm, or embankment integrity or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Infiltration Pond, Top or Side Slopes of Dam, Berm or Embankment Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Infiltration Pond, Tank, Vault, Trench, or Small Basin Storage Area Sediment accumulation If two inches or more sediment is present or a percolation test indicates facility is working at or less than 90% of design. Facility infiltrates as designed. Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Infiltration Tank Structure Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Infiltration Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-4 NO. 2 – INFILTRATION FACILITIES Maintenance Component Defect or Problem Conditions When Maintenance Is Needed Results Expected When Maintenance Is Performed Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipes Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access Manhole Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and covers access opening completely. Large access doors/plate Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. Infiltration Pond, Tank, Vault, Trench, or Small Basin Filter Bags Plugged Filter bag more than 1/2 full. Replace filter bag or redesign system. Infiltration Pond, Tank, Vault, Trench, or Small Basin Pre- settling Ponds and Vaults Sediment accumulation 6" or more of sediment has accumulated. Pre-settling occurs as designed Infiltration Pond, Rock Filter Plugged High water level on upstream side of filter remains for extended period of time or little or no water flows through filter during heavy rain storms. Rock filter replaced evaluate need for filter and remove if not necessary. Rock missing Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip-rap on inside slopes need not be replaced. Spillway restored to design standards. Infiltration Pond Emergency Overflow Spillway Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-5 NO. 3 – DETENTION TANKS AND VAULTS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Trash and debris Any trash and debris accumulated in vault or tank (includes floatables and non-floatables). No trash or debris in vault. Tank or Vault Storage Area Sediment accumulation Accumulated sediment depth exceeds 10% of the diameter of the storage area for ½ length of storage vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than ½ length of tank. All sediment removed from storage area. Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Tank Structure Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipes Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-6 NO. 3 – DETENTION TANKS AND VAULTS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access Manhole Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and covers access opening completely. Large access doors/plate Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-7 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Trash or debris of more than ½ cubic foot which is located immediately in front of the structure opening or is blocking capacity of the structure by more than 10%. No Trash or debris blocking or potentially blocking entrance to structure. Trash or debris in the structure that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the structure. Trash and debris Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Sediment Sediment exceeds 60% of the depth from the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Sump of structure contains no sediment. Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Damage to frame and/or top slab Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering structure through cracks, or maintenance person judges that structure is unsound. Structure is sealed and structurally sound. Cracks in walls or bottom Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering structure through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Structure has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Structure Ladder rungs missing or unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. T section is not securely attached to structure wall and outlet pipe structure should support at least 1,000 lbs of up or down pressure. T section securely attached to wall and outlet pipe. Structure is not in upright position (allow up to 10% from plumb). Structure in correct position. Connections to outlet pipe are not watertight or show signs of deteriorated grout. Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. FROP-T Section Damage Any holes—other than designed holes—in the structure. Structure has no holes other than designed holes. Cleanout Gate Damaged or missing Cleanout gate is missing. Replace cleanout gate. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-8 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Cleanout gate is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by one maintenance person. Gate moves up and down easily and is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Damaged or missing Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Orifice Plate Obstructions Any trash, debris, sediment, or vegetation blocking the plate. Plate is free of all obstructions and works as designed. Obstructions Any trash or debris blocking (or having the potential of blocking) the overflow pipe. Pipe is free of all obstructions and works as designed. Overflow Pipe Deformed or damaged lip Lip of overflow pipe is bent or deformed. Overflow pipe does not allow overflow at an elevation lower than design Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Metal Grates (If Applicable) Damaged or missing Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism Not Working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Manhole Cover/Lid Cover/lid difficult to Remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-9 NO. 5 – CATCH BASINS AND MANHOLES Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Sediment Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Sump of catch basin contains no sediment. Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within catch basin. Trash and debris Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Damage to frame and/or top slab Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch basin is unsound. Catch basin is sealed and structurally sound. Cracks in walls or bottom Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Structure Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-10 NO. 5 – CATCH BASINS AND MANHOLES Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Metal Grates (Catch Basins) Damaged or missing Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance. Grate is in place and meets design standards. Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism Not Working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Manhole Cover/Lid Cover/lid difficult to Remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-11 NO. 6 – CONVEYANCE PIPES AND DITCHES Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/roots Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Pipes Damaged Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Vegetation Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope. Slopes are not eroding. Ditches Rock lining out of place or missing (If Applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-12 NO. 7 – DEBRIS BARRIERS (E.G., TRASH RACKS) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed. Trash and debris Trash or debris plugging more than 20% of the area of the barrier. Barrier clear to receive capacity flow. Site Sediment accumulation Sediment accumulation of greater than 20% of the area of the barrier Barrier clear to receive capacity flow. Structure Cracked broken or loose Structure which bars attached to is damaged - pipe is loose or cracked or concrete structure is cracked, broken of loose. Structure barrier attached to is sound. Bar spacing Bar spacing exceeds 6 inches. Bars have at most 6 inche spacing. Bars are bent out of shape more than 3 inches. Bars in place with no bends more than ¾ inch. Bars are missing or entire barrier missing. Bars in place according to design. Bars Damaged or missing bars Bars are loose and rust is causing 50% deterioration to any part of barrier. Repair or replace barrier to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-13 NO. 8 – ENERGY DISSIPATERS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed. Trash and debris Trash and/or debris accumulation. Dissipater clear of trash and/or debris. Site Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Rock Pad Missing or moved Rock Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil. Rock pad prevents erosion. Pipe plugged with sediment Accumulated sediment that exceeds 20% of the design depth. Pipe cleaned/flushed so that it matches design. Not discharging water properly Visual evidence of water discharging at concentrated points along trench (normal condition is a “sheet flow” of water along trench). Water discharges from feature by sheet flow. Perforations plugged. Over 1/4 of perforations in pipe are plugged with debris or sediment. Perforations freely discharge flow. Water flows out top of “distributor” catch basin. Water flows out of distributor catch basin during any storm less than the design storm. No flow discharges from distributor catch basin. Dispersion Trench Receiving area over- saturated Water in receiving area is causing or has potential of causing landslide problems. No danger of landslides. Damaged mesh Mesh of gabion broken, twisted or deformed so structure is weakened or rock may fall out. Mesh is intact, no rock missing. Corrosion Gabion mesh shows corrosion through more than ¼ of its gage. All gabion mesh capable of containing rock and retaining designed form. Collapsed or deformed baskets Gabion basket shape deformed due to any cause. All gabion baskets intact, structure stands as designed. Gabions Missing rock Any rock missing that could cause gabion to loose structural integrity. No rock missing. Worn or damaged post, baffles or side of chamber Structure dissipating flow deteriorates to ½ or original size or any concentrated worn spot exceeding one square foot which would make structure unsound. Structure is in no danger of failing. Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch or any evidence of soil entering the structure through cracks, or maintenance inspection personnel determines that the structure is not structurally sound. Manhole/chamber is sealed and structurally sound. Manhole/Chamber Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No soil or water enters and no water discharges at the joint of inlet/outlet pipes. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-14 NO. 9 – FENCING Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Site Erosion or holes under fence Erosion or holes more than 4 inches high and 12- 18 inches wide permitting access through an opening under a fence. No access under the fence. Missing or damaged parts Missing or broken boards, post out of plumb by more than 6 inches or cross members broken No gaps on fence due to missing or broken boards, post plumb to within 1½ inches, cross members sound. Weakened by rotting or insects Any part showing structural deterioration due to rotting or insect damage All parts of fence are structurally sound. Wood Posts, Boards and Cross Members Damaged or failed post foundation Concrete or metal attachments deteriorated or unable to support posts. Post foundation capable of supporting posts even in strong wind. Post out of plumb more than 6 inches. Post plumb to within 1½ inches. Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence (including post, top rails, and fabric) more than 1 foot out of design alignment. Fence is aligned and meets design standards. Damaged parts Missing or loose tension wire. Tension wire in place and holding fabric. Deteriorated paint or protective coating Part or parts that have a rusting or scaling condition that has affected structural adequacy. Structurally adequate posts or parts with a uniform protective coating. Metal Posts, Rails and Fabric Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-15 NO. 10 – GATES/BOLLARDS/ACCESS BARRIERS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Missing gate. Gates in place. Broken or missing hinges such that gate cannot be easily opened and closed by a maintenance person. Hinges intact and lubed. Gate is working freely. Gate is out of plumb more than 6 inches and more than 1 foot out of design alignment. Gate is aligned and vertical. Damaged or missing members Missing stretcher bar, stretcher bands, and ties. Stretcher bar, bands, and ties in place. Locking mechanism does not lock gate Locking device missing, no-functioning or does not link to all parts. Locking mechanism prevents opening of gate. Chain Link Fencing Gate Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. Damaged or missing cross bar Cross bar does not swing open or closed, is missing or is bent to where it does not prevent vehicle access. Cross bar swings fully open and closed and prevents vehicle access. Locking mechanism does not lock gate Locking device missing, no-functioning or does not link to all parts. Locking mechanism prevents opening of gate. Bar Gate Support post damaged Support post does not hold cross bar up. Cross bar held up preventing vehicle access into facility. Damaged or missing Bollard broken, missing, does not fit into support hole or hinge broken or missing. No access for motorized vehicles to get into facility. Bollards Does not lock Locking assembly or lock missing or cannot be attached to lock bollard in place. No access for motorized vehicles to get into facility. Dislodged Boulders not located to prevent motorized vehicle access. No access for motorized vehicles to get into facility. Boulders Circumvented Motorized vehicles going around or between boulders. No access for motorized vehicles to get into facility. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-16 NO. 11 – GROUNDS (LANDSCAPING) Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Trash or litter Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Hazard Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon as possible. No hazard trees in facility. Limbs or parts of trees or shrubs that are split or broken which affect more than 25% of the total foliage of the tree or shrub. Trees and shrubs with less than 5% of total foliage with split or broken limbs. Trees or shrubs that have been blown down or knocked over. No blown down vegetation or knocked over vegetation. Trees or shrubs free of injury. Trees and Shrubs Damaged Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Tree or shrub in place and adequately supported; dead or diseased trees removed. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-17 NO. 12 – ACCESS ROADS Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Trash and debris exceeds 1 cubic foot per 1,000 square feet (i.e., trash and debris would fill up one standards size garbage can). Roadway drivable by maintenance vehicles. Trash and debris Debris which could damage vehicle tires or prohibit use of road. Roadway drivable by maintenance vehicles. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Any obstruction which reduces clearance above road surface to less than 14 feet. Roadway overhead clear to 14 feet high. Site Blocked roadway Any obstruction restricting the access to a 10- to 12 foot width for a distance of more than 12 feet or any point restricting access to less than a 10 foot width. At least 12-foot of width on access road. Erosion, settlement, potholes, soft spots, ruts Any surface defect which hinders or prevents maintenance access. Road drivable by maintenance vehicles. Road Surface Vegetation on road surface Trees or other vegetation prevent access to facility by maintenance vehicles. Maintenance vehicles can access facility. Erosion Erosion within 1 foot of the roadway more than 8 inches wide and 6 inches deep. Shoulder free of erosion and matching the surrounding road. Shoulders and Ditches Weeds and brush Weeds and brush exceed 18 inches in height or hinder maintenance access. Weeds and brush cut to 2 inches in height or cleared in such a way as to allow maintenance access. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Modular Grid Pavement Damaged or missing Access surface compacted because of broken on missing modular block. Access road surface restored so road infiltrates. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-18 NO. 13 – BASIC BIOFILTRATION SWALE (GRASS) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Trash and debris Any trash and/or debris accumulated on the bioswale site. No trash or debris on the bioswale site. Site Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Sediment depth exceeds 2 inches in 10% of the swale treatment area. No sediment deposits in grass treatment area of the bioswale. Sediment inhibits grass growth over 10% of swale length. Grass growth not inhibited by sediment. Sediment accumulation Sediment inhibits even spreading of flow. Flow spreads evenly through swale Erosion/scouring Eroded or scoured swale bottom due to channelization or high flows. No eroded or scoured areas in bioswale. Cause of erosion or scour addressed. Poor vegetation coverage Grass is sparse or bare or eroded patches occur in more than 10% of the swale bottom. Swale has no bare spots and grass is thick and healthy. Grass too tall Grass excessively tall (greater than 10 inches), grass is thin or nuisance weeds and other vegetation has taken over. Grass is between 3 and 4 inches tall, thick and healthy. No clippings left in swale. No nuisance vegetation present. Excessive shade Grass growth is poor because sunlight does not reach swale. Health grass growth or swale converted to a wet bioswale. Constant baseflow Continuous flow through the swale, even when it has been dry for weeks or an eroded, muddy channel has formed in the swale bottom. Baseflow removed from swale by a low-flow pea-gravel drain or bypassed around the swale. Standing water Water pools in the swale between storms or does not drain freely. Swale freely drains and there is no standing water in swale between storms. Swale Section Channelization Flow concentrates and erodes channel through swale. No flow channels in swale. Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across entire swale width. Flows are spread evenly over entire swale width. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-19 NO. 14 – WET BIOFILTRATION SWALE Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Trash and debris Any trash and/or debris accumulated at the site. No trash or debris at the site. Site Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Sediment accumulation Sediment depth exceeds 2 inches in 10% of the swale treatment area. No sediment deposits in treatment area. Erosion/scouring Eroded or scoured swale bottom due to channelization or high flows. No eroded or scoured areas in bioswale. Cause of erosion or scour addressed. Water depth Water not retained to a depth of about 4 inches during the wet season. Water depth of 4 inches through out swale for most of wet season. Vegetation ineffective Vegetation sparse, does not provide adequate filtration or crowded out by very dense clumps of cattail or nuisance vegetation. Wetland vegetation fully covers bottom of swale and no cattails or nuisance vegetation present. Swale Section Insufficient water Wetland vegetation dies due to lack of water. Wetland vegetation remains healthy (may require converting to grass lined bioswale Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across entire swale width. Flows are spread evenly over entire swale width. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-20 NO. 15 – FILTER STRIP Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Trash and debris Any trash and debris accumulated on the filter strip site. Filter strip site free of any trash or debris Site Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Sediment accumulation Sediment accumulation on grass exceeds 2 inches depth. No sediment deposits in treatment area. Erosion/scouring Eroded or scoured swale bottom due to channelization or high flows. No eroded or scoured areas in bioswale. Cause of erosion or scour addressed. Grass too tall Grass excessively tall (greater than 10 inches), grass is thin or nuisance weeds and other vegetation has taken over. Grass is between 3 and 4 inches tall, thick and healthy. No clippings left in swale. No nuisance vegetation present. Grass Strip Vegetation ineffective Grass has died out, become excessively tall (greater than 10 inches) or nuisance vegetation is taking over. Grass is healthy, less than 9 inches high and no nuisance vegetation present. Flow Spreader Concentrated flow Flow from spreader not uniformly distributed across entire swale width. Flows are spread evenly over entire swale width. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-21 NO. 16 – WETPOND Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Trash and debris Any trash and debris accumulated on the wetpond site. Wetpond site free of any trash or debris. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm or embankment integrity, are not interfering with access or maintenance or leaves do not cause a plugging problem they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Side Slopes of Dam, Berm, internal berm or Embankment Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Top or Side Slopes of Dam, Berm, internal berm or Embankment Irregular surface on internal berm Top of berm not uniform and level. Top of berm graded to design elevation. Sediment accumulation (except first wetpool cell) Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth. Sediment accumulation (first wetpool cell) Sediment accumulations in pond bottom that exceeds the depth of sediment storage (1 foot) plus 6 inches. Sediment storage contains no sediment. Liner damaged (If Applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Water level (first wetpool cell) First cell empty, doesn't hold water. Water retained in first cell for most of the year. Pond Areas Algae mats (first wetpool cell) Algae mats develop over more than 10% of the water surface should be removed. Algae mats removed (usually in the late summer before Fall rains, especially in Sensitive Lake Protection Areas.) Inoperable valve Valve will not open and close. Valve opens and closes normally. Gravity Drain Valve won’t seal Valve does not seal completely. Valve completely seals closed. Emergency Overflow Spillway Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-22 NO. 16 – WETPOND Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Rock missing Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip-rap on inside slopes need not be replaced. Spillway restored to design standards. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-23 NO. 17 – WETVAULT Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Site Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Trash and debris Any trash and debris accumulated in vault (includes floatables and non-floatables). No trash or debris in vault. Sediment accumulation Sediment accumulation in vault bottom exceeds the depth of the sediment zone plus 6 inches. No sediment in vault. Treatment Area Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks, vault does not retain water or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure or baffle cannot be removed. Repair or replace baffles or walls to specifications. Vault Structure Ventilation Ventilation area blocked or plugged. No reduction of ventilation area exists. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Inoperable valve Valve will not open and close. Valve opens and closes normally. Gravity Drain Valve won’t seal Valve does not seal completely. Valve completely seals closed. Access cover/lid damaged or difficult to open Access cover/lid cannot be easily opened by one person. Corrosion/deformation of cover/lid. Access cover/lid can be opened by one person. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access doors/plate has gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and covers access opening completely. Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. Access Manhole Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-24 NO. 18 – STORMWATER WETLAND Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm, or embankment integrity or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Side Slopes of Dam, Berm, internal berm or Embankment Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Top or Side Slopes of Dam, Berm, internal berm or Embankment Irregular surface on internal berm Top of berm not uniform and level. Top of berm graded flat to design elevation. Sediment accumulation (first cell/forebay) Sediment accumulations in pond bottom that exceeds the depth of sediment storage (1 foot) plus 6 inches. Sediment storage contains no sediment. Sediment accumulation (wetland cell) Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth. Liner damaged (If Applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Water level (first cell/forebay) Cell does not hold 3 feet of water year round. 3 feet of water retained year round. Water level (wetland cell) Cell does not retain water for at least 10 months of the year or wetland plants are not surviving. Water retained at least 10 months of the year or wetland plants are surviving. Algae mats (first cell/forebay) Algae mats develop over more than 10% of the water surface should be removed. Algae mats removed (usually in the late summer before Fall rains, especially in Sensitive Lake Protection Areas.) Pond Areas Vegetation Vegetation dead, dying, or overgrown (cattails) or not meeting original planting specifications. Plants in wetland cell surviving and not interfering with wetland function. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-25 NO. 18 – STORMWATER WETLAND Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Inoperable valve Valve will not open and close. Valve opens and closes normally. Gravity Drain Valve won’t seal Valve does not seal completely. Valve completely seals closed. Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. Emergency Overflow Spillway Rock missing Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip-rap on inside slopes need not be replaced. Spillway restored to design standards. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-26 NO. 19 – SAND FILTER POND Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Grass/groundcover (not in the treatment area) Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Sediment accumulation Sediment accumulations in pond bottom that exceeds the depth of sediment storage (1 foot) plus 6 inches. Sediment storage contains no sediment. Liner damaged (If Applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Water level Cell empty, doesn't hold water. Water retained in first cell for most of the year. Pre-Treatment (if applicable) Algae mats Algae mats develop over more than 10% of the water surface should be removed. Algae mats removed (usually in the late summer before Fall rains, especially in Sensitive Lake Protection Areas.) Sediment accumulation Sediment or crust depth exceeds ½-inch over 10 % of surface area of sand filter. No sediment or crust deposit on sand filter that would impede permeability of the filter section. Pond Area Grass (if applicable) Grass becomes excessively tall (greater than 6 inches) or when nuisance weeds and other vegetation start to take over or thatch build up occurs. Mow vegetation and/or remove nuisance vegetation. Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of dams, berms or slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat to dam, berm, or embankment integrity or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Side Slopes of Pond Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-27 NO. 19 – SAND FILTER POND Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Plugging Drawdown of water through the sand filter media, takes longer than 24 hours, and/or flow through the overflow pipes occurs frequently. A sieve analysis of >4% -100 or >2% -200 requires replacing sand filter media. Sand filter media surface is aerated and drawdown rate is normal. Prolonged flows Sand is saturated for prolonged periods of time (several weeks) and does not dry out between storms due to continuous base flow or prolonged flows from detention facilities. Excess flows bypassed or confined to small portion of filter media surface. Short circuiting Flows become concentrated over one section of the sand filter rather than dispersed or drawdown rate of pool exceeds 12 inches per hour. Flow and percolation of water through the sand filter is uniform and dispersed across the entire filter area and drawdown rate is normal. Sand Filter Media Media thickness Sand thickness is less than 6 inches. Rebuild sand thickness to a minimum of 6 inches and preferably to 18 inches. Underdrains and Clean-Outs Sediment/debris Underdrains or clean-outs partially plugged or filled with sediment and/or debris. Junction box/cleanout wyes not watertight. Underdrains and clean-outs free of sediment and debris and are watertight. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Rock Pad Missing or out of place Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil. Rock pad restored to design standards. Flow spreader Concentrated flow Flow from spreader not uniformly distributed across sand filter. Flows spread evenly over sand filter. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-28 NO. 20 – SAND FILTER VAULT Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Pre-Treatment Chamber Sediment accumulation Sediment accumulation exceeds the depth of the sediment zone plus 6 inches. Sediment storage contains no sediment. Sediment accumulation Sediment depth exceeds ½-inch on sand filter media. Sand filter freely drains at normal rate. Trash and debris Trash and debris accumulated in vault (floatables and non-floatables). No trash or debris in vault. Plugging Drawdown of water through the sand filter media, takes longer than 24 hours, and/or flow through the overflow pipes occurs frequently. A sieve analysis of >4% -100 or >2% -200 requires replacing sand filter media. Sand filter media drawdown rate is normal. Sand Filter Media Short circuiting Seepage or flow occurs along the vault walls and corners. Sand eroding near inflow area. Cleanout wyes are not watertight. Sand filter media section re-laid and compacted along perimeter of vault to form a semi-seal. Erosion protection added to dissipate force of incoming flow and curtail erosion. Damaged to walls, frame, bottom and/or top slab. Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to provide complete sealing of the structure. Vault Structure Ventilation Ventilation area blocked or plugged. No reduction of ventilation area exists. Underdrains and Cleanouts Sediment/debris Underdrains or clean-outs partially plugged, filled with sediment and/or debris or not watertight. Underdrains and clean-outs free of sediment and debris and sealed. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-29 NO. 20 – SAND FILTER VAULT Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access Manhole Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and covers access opening completely. Large access doors/plate Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-30 NO. 21 – STORMFILTER (CARTRIDGE TYPE) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Any evidence of contaminants or pollution such as oils, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Site Life cycle System has not been inspected for three years. Facility is re-inspected and any needed maintenance performed. Sediment on vault floor Greater than 2 inches of sediment. Vault is free of sediment. Sediment on top of cartridges Greater than ½ inch of sediment. Vault is free of sediment. Vault Treatment Area Multiple scum lines above top of cartridges Thick or multiple scum lines above top of cartridges. Probably due to plugged canisters or underdrain manifold. Cause of plugging corrected, canisters replaced if necessary. Damage to wall, Frame, Bottom, and/or Top Slab Cracks wider than ½-inch and any evidence of soil particles entering the structure through the cracks, or qualified inspection personnel determines the vault is not structurally sound. Vault replaced or repaired to design specifications. Vault Structure Baffles damaged Baffles corroding, cracking warping, and/or showing signs of failure as determined by maintenance/inspection person. Repair or replace baffles to specification. Standing water in vault 9 inches or greater of static water in the vault for more than 24 hours following a rain event and/or overflow occurs frequently. Probably due to plugged filter media, underdrain or outlet pipe. No standing water in vault 24 hours after a rain event. Filter Media Short circuiting Flows do not properly enter filter cartridges. Flows go through filter media. Underdrains and Clean-Outs Sediment/debris Underdrains or clean-outs partially plugged or filled with sediment and/or debris. Underdrains and clean-outs free of sediment and debris. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access Manhole Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-31 NO. 21 – STORMFILTER (CARTRIDGE TYPE) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-32 NO. 22 – BAFFLE OIL/WATER SEPARATOR Maintenance Component Defect Condition When Maintenance is Needed Results Expected When Maintenance is Performed Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Site Contaminants and pollution Floating oil in excess of 1 inch in first chamber, any oil in other chambers or other contaminants of any type in any chamber. No contaminants present other than a surface oil film. Sediment accumulation Sediment accumulates exceeds 6 inches in the vault. No sediment in the vault. Discharge water not clear Inspection of discharge water shows obvious signs of poor water quality- effluent discharge from vault shows thick visible sheen. Effluent discharge is clear. Trash or debris accumulation Any trash and debris accumulation in vault (floatables and non-floatables). Vault is clear of trash and debris. Vault Treatment Area Oil accumulation Oil accumulations that exceed 1 inch, at the surface of the water in the oil/water separator chamber. No visible oil depth on water. Damage to Wall, Frame, Bottom, and/or Top Slab Cracks wider than ½-inch or evidence of soil particles entering the structure through the cracks, or maintenance/inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to design specifications. Vault Structure Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure as determined by maintenance inspection personnel. Repair or replace baffles to specifications. Inoperable valve Valve will not open and close. Valve opens and closes normally. Gravity Drain Valve won’t seal Valve does not seal completely. Valve completely seals closed. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access Manhole Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Large access doors/plate Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or cover/lid. Lifting rings sufficient to lift or remove cover/lid. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-33 NO. 23 – COALESCING PLATE OIL/WATER SEPARATOR Maintenance Component Defect Condition When Maintenance is Needed Results Expected When Maintenance is Performed Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Site Contaminants and pollution Floating oil in excess of 1 inch in first chamber, any oil in other chambers or other contaminants of any type in any chamber. No contaminants present other than a surface oil film. Sediment accumulation in the forebay Sediment accumulation of 6 inches or greater in the forebay. No sediment in the forebay. Discharge water not clear Inspection of discharge water shows obvious signs of poor water quality - effluent discharge from vault shows thick visible sheen. Repair function of plates so effluent is clear. Trash or debris accumulation Trash and debris accumulation in vault (floatables and non-floatables). Trash and debris removed from vault. Vault Treatment Area Oil accumulation Oil accumulation that exceeds 1 inch at the water surface in the in the coalescing plate chamber. No visible oil depth on water and coalescing plates clear of oil. Damaged Plate media broken, deformed, cracked and/or showing signs of failure. Replace that portion of media pack or entire plate pack depending on severity of failure. Coalescing Plates Sediment accumulation Any sediment accumulation which interferes with the operation of the coalescing plates. No sediment accumulation interfering with the coalescing plates. Damage to Wall, Frame, Bottom, and/or Top Slab Cracks wider than ½-inch and any evidence of soil particles entering the structure through the cracks, or maintenance inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to design specifications. Vault Structure Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure as determined by maintenance/inspection person. Repair or replace baffles to specifications. Ventilation Pipes Plugged Any obstruction to the ventilation pipes. Ventilation pipes are clear. Shutoff Valve Damaged or inoperable Shutoff valve cannot be opened or closed. Shutoff valve operates normally. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Inlet/Outlet Pipe Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Access Manhole Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1/9/2009 2009 Surface Water Design Manual – Appendix A A-34 NO. 23 – COALESCING PLATE OIL/WATER SEPARATOR Maintenance Component Defect Condition When Maintenance is Needed Results Expected When Maintenance is Performed Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Large access doors/plate Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 2009 Surface Water Design Manual – Appendix A 1/9/2009 A-35 NO. 24 – CATCH BASIN INSERT Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Visible Oil Visible oil sheen passing through media Media inset replaced. Insert does not fit catch basin properly Flow gets into catch basin without going through media. All flow goes through media. Filter media plugged Filter media plugged. Flow through filter media is normal. Oil absorbent media saturated Media oil saturated. Oil absorbent media replaced. Water saturated Catch basin insert is saturated with water, which no longer has the capacity to absorb. Insert replaced. Service life exceeded Regular interval replacement due to typical average life of media insert product, typically one month. Media replaced at manufacturer’s recommended interval. Media Insert Seasonal maintenance When storms occur and during the wet season. Remove, clean and replace or install new insert after major storms, monthly during the wet season or at manufacturer’s recommended interval.